mabry FieldTrip Guidebook - SVSD SharePoint Web Site

Field Trip Guidebook to the Natural
History of Kittitas County
Jana Jones Mabry
Acknowledgments
This book was made possible by the gracious support of numerous
individuals, all of whom deserve many thanks.
First, to my graduate committee; Dr. Lisa Ely, Chair, Dr. Jim
Huckabay, and Dr. Morris Uebelacker all of whom have been teachers,
mentors, and friends throughout my undergraduate and graduate studies, and
Dr. Anne Denman for supporting my ideas with avenues for funding.
Second, the financial support and encouragement supplied by an
anonymous donor of the Science and Literature Scholarship and the Leo
Thayer Grant that provided the funds for printing and sharing it with
everyone else.
Third, to my family who gave me moral, financial, and sometimes
physical support, who cheered me on, made considerable sacrifices, and
followed and helped in the field.
And last, but not least, the MANY individuals whose life work it has
been to study and share the wonders of this special place with everyone else,
and inspired me to share it further: Dr. Robert Bentley, Dr. Newell P.
Campbell, Dr. Martin Kaatz, and Jack Powell, whose illustrations fill this
guidebook.
Dedication
To Bishop and the children of Kittitas County Washington, may this
always be a beautiful and special place for you to live and learn the wonders
of the world. Use this book to find the connections to your world and each
other.
1
Table Of Contents
Page #’s
Acknowledgements and Dedication .................................................... 1
An Outdoor Etiquette........................................................................... 4
Kittitas County Professionals ...........................................................5-6
How to use this Book ........................................................................... 7
What Are Natural and Cultural Resources? ......................................... 8
Introduction........................................................................................... 9
What is the Environment?................................................................... 10
The Geologic History of Washington State...................................11-15
The Natural History of Kittitas County .............................................. 16
A Tour of the Geology along Interstate 90 from Snoqualmie Pass
to the Columbia River....................................................................17-20
A Guided Tour Under Ellensburg..................................................21-22
A Guided Tour of Craig’s Hill ......................................................24-26
Where Does Ellensburg’s Water Come From? .............................28-29
A Guided Tour of Yakima Canyon ...............................................30-44
The Thorp – Teanaway Glacial Features Guided Tour .................45-53
An Overview Tour of the Liberty, Red Top, Swauk and
Blewett Areas.................................................................................54-63
The Ginkgo and Vantage Guided Tour .........................................64-66
Glossary of Terms..........................................................................67-72
2
Table of Maps and Figures
Maps
Map 1. Kittitas County, I-90 Snoqualmie Pass to the Columbia River17
Map 2. Guided Tour of Yakima Canyon ............................................ 30
Map 3. Lookout Mountain Circle – Glacial Features......................... 45
Map 4. Liberty, Red Top, and Swauk ................................................ 54
Figures
Figure 1. Overview of the Geologic History of Washington State .... 11
Figure 2. Snoqualmie Pass to Vantage, Elevation and Climate ......... 16
Figure 3. A Field Trip 50,000 Feet beneath Ellensburg ..................... 21
Figure 4. Stratigraphy of Craig’s Hill................................................. 24
Figure 5. Cross-section of the Kittitas Valley .................................... 26
Figure 6. Ellensburg Basin.................................................................. 28
Figure 7. Anticline & Syncline Map................................................... 32
Figure 8. Ellensburg Formation in the Yakima Canyon..................... 33
Figure 9. Beaver Tail Meander and Landslides.................................. 35
Figure 10. Debris fans created by intense rainfall June 1998............. 36
Figure 11. Basalt Colonnade............................................................... 37
Figure 12. Basalt Layers and Structure............................................... 37
Figure 13. Abandoned Meander and debris fan features.................... 39
Figure 14. Mt. Baldy and Umtanum Anticline................................... 41
Figure 15. Selah Butte ........................................................................ 43
Figure 16. Glaciers and their extension into Kittitas County ............. 46
Figure 17. Thorp Gravels.................................................................... 48
Figure 18. Ellensburg Formation on S.R. 10 ...................................... 48
Figure 19. Glacial Terraces in the Upper Yakima River Canyon ...... 49
Figure 20. Terraces along S.R. 10 Yakima River Canyon ................. 50
Figure 21. Conglomerate and Mudflow Units along S.R. 10............. 51
Figure 22. Overview of the Geology from Red Top Lookout............ 57
3
An Outdoor Etiquette
When hiking, exploring, or camping in the natural environment, it is
important to remember that your being there impacts that place forever. The
place is most likely the home of numerous other life forms, some possibly rare
and fragile, that could be devastated by even a single footprint.
Etiquette is an accepted code of social behavior. It guides the way
individuals or groups act in different situations. These behaviors insure that the
largest numbers of people are accommodated, and that no one is harmed or
comes away from the experience with bad feelings.
You are probably already familiar with many different types of etiquette,
such as how you act in a library, a church, or your classroom. These etiquettes
are different than the ones experienced at a football game, a pep rally, or a
fireworks display.
“An outdoor etiquette protects both the visitors and the visited.”
The first rule of the outdoor etiquette is to “ Leave No Trace.”
1) This simply means that when you leave a place, it is exactly as you
found it.
Leave no trash.
Leave no damage.
Leave the plants and animals undisturbed.
Leave all of the pieces of the environment intact.
* Take only small amounts of what you need when
instructed by a teacher to take samples.
* Take only as directed so not to cause future harm.
2) This includes:
Keeping cars on the roads and feet on the trails.
Knowing and observing the all rules and regulations.
Observing all direction and warning signs.
“The best rule is to “ Leave it better than you found it.”
Pick up trash found on the trail.
Report damages to the authorities.
Report vandalism to the authorities.
Always let the professionals, who are experts, take care of any problems
related to the trails, buildings, visitors, or plants and animals. This practice will
provide for the safety of everyone. See the following page for a list of the
Kittitas County Professionals responsible for information related to the region’s
natural resources.
Kittitas County Area Professionals
4
In Wenatchee WA:
Wenatchee National Forest District
Wenatchee National Forest - Supervisor’s Office
301 Yakima St
Wenatchee, WA 98807 Phone: (509) 662-4335
U.S. Department of the Interior
Bureau of Land Management
915 Walla Walla Ave.
Wenatchee, WA 98901 Phone: (509) 665-2100
In Ellensburg, WA:
The Ellensburg Chamber of Commerce
Wenatchee Nation Forest Service Contract Office
801 South Ruby Phone: (509) 962-9813
Department of Natural Resources - Area Headquarters
713 Bowers Road
Phone: (509) 925-8510
Kittitas County Museum
114 E 3rd
(509) 925-3778
Central Washington Archaeological Survey
Department of Anthropology, Farrell Hall
Central Washington University
(509) 963-1804
I-DEAS Gateway
500 N. Ruby Street
(509) 925-5537
Doreen Tanenbaum
Kittitas Environmental Education Network (KEEN)
812 East 8th Ave.
(509) 925-2887 OR (509) 933-4008
In Cle Elum-Roslyn, WA:
5
Wenatchee National Forest Service - Cle Elum Ranger District
803 West Second
Phone: (509) 674-4411
Cle Elum Chamber of Commerce
401 West 1st Street
(509) 674-5958
In Vantage, WA:
Ginkgo State Park
29 Miles East of Ellensburg on I-90
Phone: (509) 856-2290
Ginkgo Petrified Forest Manager (509) 856-2700
Wamapum Dam and Heritage Center
P.O. Box 878, Ephrata, WA 98823
1-800-422-3199 Ext. #2571 or (509) 932-3571
In Yakima, WA:
Washington Department of Fish & Wildlife
1701 South 24th Ave.
Yakima, WA 98902-5720
(509) 575-2740
Yakima Nation Heritage Center
100 Spilyay Loop, P.O. Box 151
(509) 865-2806
Washington State Parks & Recreation Commission
7150 Clearwater Lane - PO Box 42650
Olympia, Washington 98504-2650
Information Line 1-800-233-0321
6
How to use this Book
Reestablishing our connections to the natural world is seen as a way to
preserve and protect our natural resources for future generations. Generations of
people have developed their love and respect of nature from their connection to
the many special places found in this region. Their stories fill our libraries and
attest to the life-long pleasure that growing up here has provided them.
Use this book to learn about the many unique geologic features of the
Kittitas Valley and surrounding areas. Use it to understand the natural history
and nature of this place, and its importance to the other life forms with which
we share it. Use it to experience the taste of the rain and water, the smell of
sagebrush in the wind, and the color of the wildflowers. Use it to watch the
spawning of salmon, the flight of birds, the growth of plants, and the migration
of bighorn sheep, black-tailed dear, and elk.
Know as you walk along the many trails that others like William O.
Douglas and Chief Seattle have walked these same trails. Use these trails to
discover life, beauty, peace and inspiration as they did. Use this book to find
your connections with nature and the natural world.
Each individual trip calculates the mileage from different beginning
points in Ellensburg. The points will be local landmarks or clearly posted signs
where the odometer of your car is to be set at zero (0). The mileage from the
beginning point of each trip will indicate the special features emphasized. The
guidebook tours point in the direction of travel. The underlined terms in the text
of the guidebook can be found in the glossary at the end.
What are Natural and Cultural Resources?
Natural Resources are all the elements required for life. The elements
make up the air, water, soil, plants, animals, and scenery surrounding us and the
whole world. Resources can be microscopic or as large as a mountain range.
They are all connected to each other in the dynamic web of life.
Cultural resources are everything a culture considers important to the
well being of their people. Cultural resources are often the same resources as
the ones we consider to be natural resources, but these resources also have
inspirational, aesthetic, or spiritual values. Both natural and cultural resources
nourish our bodies and minds and enrich the environment and experiences we
have.
7
Introduction
Natural history is the study of natural objects and organisms with
reference to their origins and their evolution within a native environment. Why
study the natural history of a place? A fundamental concept in the natural
sciences is the principal of uniformatarianism. This concept, “The present is the
key to the past,” was first proposed by geologist James Hutton and has been
used since by science to help us to understand and to simplify the complexities
of the world around us today and into the past.
Natural history helps us to put into perspective the temporal scale in
which natural events occur, instead of in a human-constructed time scale. This
understanding is crucial to the decisions we make everyday because it directly
affects the outcomes of those decisions. This knowledge gives each individual
the power to make a difference in the quality of all life, in our own homes as
well as on our planet.
As we enter a new millennium our understanding of the natural world
becomes increasingly important as we address important problems that face
future generations and us. We are reminded daily that the availability of natural
resources on our planet is limited. The ability of our planet to provide
renewable resources, like clean water, is already at a threshold in many places.
How we manage our remaining natural resources will determine the quality of
life for all creatures of our planet for generations to come.
Humans have the greatest responsibility toward all life on the planet,
because we have the greatest impact on it. We have the power to completely
destroy most of the life on Earth or enhance it based on our knowledge and our
collective will. If we are to coexist with other biological life forms, then we
must recognized the life and space requirements of those life forms. We as
humans ultimately will decide who and what lives, and who and what dies.
For over a generation, the scientific community has sounded alarms
concerning our environment, and the need for increased attention to the impact
of humans on the environment. Our individual impacts count in the quality of
our environment. If enough people individually change their negative impacts
on the environment we can collectively make a difference that will preserve
natural resources for future generations.
Reestablishing our connections to the natural world will help us to
understand and use our resources wisely. They are very limited and must last
for generations to come. It is important for each individual to understand how
we use resources and to “use what you need, but need what you use.”
Remembering this becomes easier as you interact with the natural environment
8
and understand the relationships between the landscape and the plants and
animals.
Life on our planet is a complex web of relationships that connects
everything. Humans are also part of the living natural system. The terms
environment and ecosystem are the words we use to describe living systems,
but are often misunderstood to mean only those things that are not human.
Humans like all other living creatures live in and are part of the environment.
Our relationships with the other parts of the system, sets in motion a whole
range of actions and changes. These actions and changes can be positive and
enhance life or negative and destroy life and the elements necessary for it.
What is the environment?
The environment is everything around you. It can be living, like a forest,
or nonliving like a rock or a mountain. An environment can be natural or it can
be man-made. There are many kinds of environments, such as oceans, lakes,
grasslands, forests, tundra, deserts and more. Kittitas County contains many of
these environments due to its location; it is near the ocean, next to the Cascade
Mountains, on top of different geological deposits and it changes 2420 feet in
elevation from the mountains to the Columbia River. Because of its location,
changes can occur rapidly causing the boundaries between different
environments to shift.
Every environment contains a combination of nonliving things like air,
water, or soil as well as living things like birds, fish, insects and plants. No
living thing can live alone. Every living thing depends upon and interacts with
other living and nonliving things in its environment. Many plants and animals
are only found in one kind of environment and depend on just the right
conditions to be successful at life.
A little change is not always good for the environment, and a lot of
change is not always bad for the environment. For example, people can walk
through the forest and just look. People can cut only a few trees from a large
area and still not change the interrelationships. Some things that people do
cause a lot of change. Cutting down a forest to grow crops, build houses, or
make paper can change the interactions within an entire environment. When
people make bad choices, then interrelationships within environments are often
harmed.
The environment holds all of our natural and cultural resources. Different
environments contain different types and kinds of resources. And different
resources determine differences in how life is lived in that environment. How
those resources are managed depends on what we understand about our
9
environments and our interactions with them. Understanding how those natural
resources came to exist is the study of natural history.
Natural history helps us to understand the limitations of the natural
resources of our region. That understanding helps us to realize our connections
to everything else and our position in the web of life.
What is an Ecosystem?
An ecosystem is a collection of relationships that includes every single
element and combination of elements found in a system. Everything in our
world is made up of single chemical elements that combine to create the variety
and diversity of living and nonliving formations. The composition of forms
dictates whether a thing becomes air, a rock, a plant, a dog, or a human.
Ecology is the science that studies the relationships between the different
elements and forms within a system, specifically the interactions between the
non-living and living forms.
Literature on the Environment and Ecosystems
Bang, Molly, 1997. Common Ground: The Water, Earth, and Air We Share.
New York: Blue Sky Press.
Bash, Barbara, 1994. Ancient Ones: The world of the Old Growth Douglas Fir.
San Francisco: Sierra Club Books for Children.
Capra, Fritjof, 1991. The Web of Life. New York: Double Day. ADULT LIT.
Farb, Peter, 1963. Ecology. New York: Time, Inc.
Seattle, Chief (1790-1866), 1991. Brother Eagle, Sister Sky: A message from
Chief Seattle. New York: Dial Books.
Internet Resources for Natural History and Science
The Smithsonian Resource Guide for Teachers has the most up-to-date
list of literature and links, appropriate for young readers, on natural history and
science and can be found at [http://www.si.edu/] under Smithsonian Resource
Guide for Teachers.
10
Figure 1. Overview of the Geologic History of Washington State
(Modified from Alt 1984; Powell 1989.)
11
The Geologic History of Washington State
The natural history of Washington State is, and has been, one of
continuous change. The landscape has changed throughout time as a result of a
diversity of natural processes. Plate tectonics is the geologic process that
physically formed the structural foundation of the region. This foundation is
collectively called the geology, and its variety is so rich that it is both
interesting and complicated to understand.
Interaction of the geology and atmospheric processes create the climatic
conditions that we, the animals and plants experience. Climate conditions are
subject to change as well, and throughout time this region has experienced very
drastic climatic changes that have affected all other forms of biological life.
Life forms exist where the conditions suit them best. They have a range
of temperatures and conditions in which they can live, and must adapt, move, or
die out as a result of changing conditions. The variety of plants and animals in
this region has changed through time as a result of all of these natural processes.
A record of all these processes conditions, animals, and plants are stored in the
earth to be discovered by those with a sense of curiosity.
How it Began:
The coast of Washington and the North American Continent was once
located at about 30 miles from the Washington - Idaho border. For about 600
million years (800 to 200 million years ago) the continent remained relatively
quiet, slowly building a broad coastal plain and a continental shelf. About 190
to 160 million years ago this belt of sedimentary materials was crushed into the
North American continent by the arrival of a new micro-continent, called the
Okanogan, which was conveyed by plate tectonics into the coastline. The
sedimentary materials were folded into the North American continent, much
like a rug pushed into a wall, and some of the rocks stand nearly vertical. This
area of deformed sedimentary rocks is called the Kootenay Arc and extends into
British Columbia.
The Okanogan micro-continent is made up of granite rocks different than
those of the North American continent. It was recognized as being different
even before scientists understood how it arrived and was added to the North
American plate. The Okanogan granite rocks were part of an island formed
somewhere else on the globe. The island continent traveled eastward toward the
North American plate until it ran into it, and accreted onto it. The island then
became part of Washington and the North American continent some time
between 175 and 100 million years ago.
12
The next major addition came with the arrival of the North Cascade
Terranes. This micro-continent is believed to have been made up of six different
terranes that were once a group of individual islands. The terrane jammed into
the new coastline from 90 to 100 million years ago.
Each individual terrane can be distinguished by its unique rock type. This
patchwork of terranes forms the foundation of the North Cascades and is topped
with volcanic materials. Volcanoes existed both before and after the arrival of
the North Cascade terranes and complicate the interpretation of the geology.
The next terrane arrived shortly after the North Cascades terrane. Called
the Insular terrane, it was moving in as the North Cascades terrane was being
pushed into and over the new coastline formed by the docking of the Okanogan
terrane. The thicknesses of the sedimentary rocks located between each docking
event are clues to the time between the events.
The last event to add to the Washington coastline was about 25 million
years ago in the areas of the Puget lowlands, Olympic Peninsula, and the
Willapa Hills. The Crescent terrane is believed to be a portion of ocean crust
that was stranded between an extinct trench and the trench lying off the coast
today. The rocks that make up these areas are old ocean crust. These ocean
crust rocks now lie as much as 2 miles higher than the present ocean floor.
Scientists believe that the tectonic process that created the earlier docking
events were very similar, but somehow the more buoyant rocks were carried
underneath the continental crust, then escaped and pushed up the coastline and
the area making up the Olympic Peninsula. It would be much like holding a
balloon under water, when you released the pressure the balloon would always
float up to the top, along with anything above it.
More changes occurred to the landscape with the eruptions of the
Columbia River Basalt Group, often referred to as the CRBG. A significant
portion of Washington State was covered by a plateau basalt province between
17.5 and 6 million years ago. These basalt flows originated from fissures and
cracks called dike swarms located about where Washington, Oregon and Idaho
meet. It is currently suggested that as many as 300 flows were erupted, creating
the Columbia Plateau. Evidence of the magnitude of the flood basalt flow can
be seen throughout the region and is discussed at different exposure points
within the individual guided tours.
The last significant events to contribute to the landscape features seen in
our area were those pertaining to ice sheets and glaciers. The Kittitas Valley
region is blanketed with the debris left by both advancing and retreating glacial
events occurring from about 2 million years ago to less than 500 years ago.
Huge moraines mark the farthest advance of many glaciers, river terraces
mark different glacial events, glacial outwash and loess make up the majority of
13
the rich farmland in production today. Most of the sharp features seen on the
highest peaks and the smooth depressions now occupied by lakes are strong
evidence of the sculpting power of glaciers.
Other Literature on Washington Geology
Allen, John E. and Marjorie Burns, 1986. Cataclysms on the Columbia.
Portland: Timber Press.
Alt, David D. and Donald W. Hyndman, 1984. Roadside Geology of
Washington State. Missoula: Mountain Press.
________, 1995. Northwest Exposures: A geologic Story of the Northwest.
Mountain Press: Missoula, Montana.
Glover, Sheldon L., 1949. Origin and Occurrence of Gem Stones in
Washington. Washington State Department of Conservation and
Development.
Harris, Stephen L., 1988. Fire Mountains of the West: The Cascade and Mono
Lake Volcanoes. Missoula: Mountain Press.
Hodges, L.K. 1897. (Ed) Mining in the Pacific Northwest: A Complete
Review of the Mineral Resources of Washington and British Columbia.
The Seattle Post Intelligencer: Washington.
Jackson, Bob. 1978. The Rockhound’s Guide to Washington. Vol. 1.Jax
Products: Renton Washington. University of Washington Special
Collections on the Pacific Northwest.
Kruckeberg, Arthur R., 1991. The Natural History of Puget Sound Country.
Seattle: University of Washington Press.
Mackin, J. Hoover and Allen S. Cary, 1965. “Origin of Cascade Landscapes.”
State of Washington Division of Mines and Geology, Information
Circular No.41.
Mason, Charles L., 1996. The Geological History of the Wenatchee Valley
and adjacent vicinity. Gig Harbor Press: Washington.
Moen Wayne S. and Marshall T. Hunting, 1975. “Handbook for Gold
14
Prospectors in Washington.” Washington Department of Natural
Resources Information Circular 57.
Mueller, M. and T. Muller, 1997. Fire, Faults, and Floods. Moscow:
University of Idaho Press.
Orr, Elizabeth L. and William N. Orr, 1996. Geology of the Pacific
Northwest. New York: McGraw Hill.
Powell, Jack, 1997. “Geology of Washington State Puzzle”. Department of
Natural Resources. Unpublished Illustration.
Tucker, Glenda B. and James G. Rigby, 1998. “Bibliography of the Geology of
the Columbia Basin and Surrounding Areas of Washington with Selected
References to Columbia Basin Geology of Idaho and Oregon.”
Department of Natural Resources Open File Report of 78-3.
Internet Sites On Washington Geology
Plate Tectonics of the Northwest Region,
“Juan de Fuca Subduction”
[http://vulcan.wr.usgs.gov/Glossary/PlateT...ics/Mapsmap_juan_de_fuca_subduction.html].
Lava Plateaus and Flood Basalts
[http://vulcan.wr.usgs.gov/Glossary/LavaPlateaus/description_lava_plateaus.html].
Ice Sheets and Glaciations
[http://vulcan.wr.usgs.gov/Glossary/Glaciers/IceSheets/description_ice_sheets.html].
15
The Natural History of Kittitas County
The natural history of Kittitas County is as action-packed as any cowboy
western. The region has experienced large and extensive changes throughout
geologic time. These changes have sculpted the landscape we see today, and are
responsible for the diversity of the geology and biology of the past and today.
From Snoqualmie Pass to Vantage, both the landscape and biological
communities change significantly. This change is primarily due to the
distribution of water across the landscape. On the western side of the Cascade
Range, precipitation levels are much greater. The mountains block most of the
rain clouds from reaching the eastern side, creating a rain shadow effect.
As you travel from Snoqualmie Pass down Interstate 90 toward the
Columbia River you’ll pass through a number of different plant communities. A
change in the plants suggests that something is going on to cause these changes.
Those causes are due to changes in the geology and soil types, precipitation
and/or temperature differences, changes in elevation, and/or change in the
direction of sun exposure. Small changes make for big differences in resources
for life.
Elevation and Climate from Snoqualmie Pass to
Vantage, Washington
Temperature
Degrees F &
Precipitation in
Inches
Precipitation
120
100
80
60
40
20
0
3020 Feet
Snoqualmie
Pass
2020 Feet
Cle Elum
1500 Feet
Ellensburg
600 Feet
Vantage
Location and Elevation
Figure 2. Snoqualmie Pass to Vantage, Washington Elevation and Climate
16
Map 1. An Overview of Kittitas County Roads and Highways.
The field trips routes found in this book are:
1) Snoqualmie Pass to Vantage, Washington along Interstate 90.
2) Beneath Ellensburg and at Craig’s Hill.
3) Yakima Canyon on State Route 821.
4) On the Canyon Road between Ellensburg and Cle Elum, Washington
along State Routes 10, 970 and U.S. Route 97.
5) From Virden, Washington at the junction of State Route 970 and U.S.
Route 97, to the top of Blewett Pass on U.S. Route 97.
6) From Ellensburg to Vantage, Washington on the “Old Vantage
Highway” that runs parallel and to the North of I-90
17
An Overview Tour of the Geology along Interstate 90 from
Snoqualmie Pass to the Columbia River
Our trip begins at the top of Snoqualmie Pass on Interstate 90 where
Kittitas County begins (SET ODOMETER At 0). The rock outcrops seen on
either side of the road are made up of the glacially carved Naches formation and
granite of the Snoqualmie Batholith. The Snoqualmie Batholith (17 to 25
million years old) intruded the Naches formation (40 to 45 million years old).
The Naches formation is a thick pile of volcanic rocks interbedded with
sandstones, on top of and surrounding the Snoqualmie Batholith. The Naches
formation can be seen from the pass summit to just east of Lake Kachess on
both sides of I-90. The Snoqualmie Batholith is exposed from the middle fork
of the Snoqualmie River, west of the pass, to about Gold Creek that feeds into
Keechelus Lake. I-90 crosses the northernmost portion of the lake at 3.0 miles
on the odometer, and runs along the north side of the lake for the next 5.5 miles
to about 9.0 miles on the odometer.
Keechelus Lake is the first of three glacially carved lakes along this route and is
the headwaters for the Yakima River and the Pleistocene Yakima Glacier. As
you look back from this area the classic U-shaped glacial valley can be seen.
The largest glacier filled the valley and flowed to the Thorp Prairie, about 13
miles east of Cle Elum. The width of the valley walls and flat debris filled
valley floors mark the significance of glacial materials on the landscape.
The sharp features of the high peaks are also the result of glacial carving
and glacial striations can be found on the exposed bedrock in many places. The
next two lakes are Kachess and Cle Elum. Kachess can be seen for about a mile
on the north side of I-90 from about 15.5 to 16.5 on the odometer. Easton Ridge
runs along the north side of I-90 from Kachess to the Roslyn exit at 29.5 miles
on the odometer.
From Kachess Lake to town of Cle Elum (from 16.5 to about 33 miles on the
odometer) the exposed bedrock is made up of the Teanaway formation. This
rock formation was extruded by dike swarms about 37 to 49 million years ago.
The formation is made up primarily of basalt lava that takes on a very dark
brown to rusty red color depending on its exposure. This formation is famous
for the Ellensburg blue agates collected by the area residents. The “blues” are
made of quartz that filled the spaces left by gas bubbles (vesicles) in the basalt.
Glacial scouring, weathering and erosion have washed the basalt and its
passenger “blues” throughout the region. The out-washed quartz “blues” have
outlived their Teanaway Basalt host rock, due to the durability of quartz, and
can be found within the Ellensburg Formation.
18
The next exposure along this route is called the Roslyn Formation and
occurs from Cle Elum (at 33 miles on the odometer) and to the northwest. This
formation is responsible for the coal mined in this area for nearly 100 years.
The Roslyn Formation is believed to have been an old swampy coastal plain 37
to 47 million years old. It is made up of arkosic sandstone, shale, and coal beds
that contain numerous plant and animal fossils. A museum depicting the coal
mining activities of this region is found in the town of Roslyn about 5 miles
northwest of Cle Elum on State Route 903.
About 7 miles east of Cle Elum (40 miles on the odometer) the first
glimpses of the Columbia River Basalt Plateau are seen where the Yakima
River has cut into the westernmost edge of the plateau. I-90 drops through the
Thorp Drift (from 51 to 54 miles on the odometer) which marks the oldest and
furthest reaching known glacial moraine in the valley. Changes in the types of
vegetation become more evident in this area. The changes are the result of a
drop in elevation of about 1520 feet from the Pass (3020 feet) to Ellensburg
(1500 feet), and a significant drop in precipitation of about 107 inches average a
year at the summit of Snoqualmie Pass, to about 8 inches average a year at
Ellensburg (Figure 1).
At the bottom of the Thorp Drift moraine the view opens up into the
Kittitas Valley which is deeply buried in river gravel deposited by the ancient
Yakima River. This valley is a syncline that creates the Ellensburg Basin
located between Mission Ridge to the north and Manastash Ridge to the south.
The Ellensburg Basin holds nearly 4000 feet of rock, sand, and gravel that
accumulated over a period of 2 to 10 million years. The basin is formally called
the Ellensburg Formation and is discussed in greater detail later in this book.
The Ellensburg Formation (Figure 6) is the predominant sedimentary
structure in the basin. The largest outcrop in this area underlies the water tower
on Craig’s Hill, located to the south of the Ellensburg Rodeo Grounds. The
sediments that make up this formation are inter-layered gravely sediments,
volcanic debris and topped with wind blown loess. Remnants of the Ellensburg
Formation can be found throughout this region and are popular hunting spots
for “blues.”
From Ellensburg to the Columbia River at Vantage, the landscape is
shaped by the underlying Grande Ronde Basalt Group of Columbia Plateau
Basalt Formation, and the climate continues to get dryer as the elevation drops
about another 900 feet, to 600 feet at the Columbia River. The vegetation
changes into a temperate grassland region called a steppe, and sagebrush
becomes the predominant plant seen along this route. This area is called the
Quilomene Wildlife Recreation Area and is flanked to the south by the
Boylston and Saddle Mountains.
19
Interstate-90 continues to cut into the bedrock and many of the road-cuts
along this route provide interesting features formed within the individual
exposed basalt flows. Both pillow and columnar basalt features are found in the
road-cuts and provide clues to the environment into which the lava flowed.
Pillow basalt forms from the contact of lava with water and creates individual
rounded features that are easily seen from the road. Columnar structures are
formed as the result of slowly cooled lava, and are also visible along this route.
Central Washington State College Professor George F. Beck discovered
an intriguing natural history mystery of the county in 1931. The Ginkgo
Petrified Forest is one of the most unique and scientifically important
geological features in the state and is recognized as a Registered National
Natural Landmark. The Ginkgo Petrified Forest State Park is located 1.25 miles
north of Vantage. It consists of an Interpretive Center along the banks of the
Columbia River and an Interpretive Trail located 3 miles west of Vantage. The
Ginkgo tree is one of the 30 species of petrified trees found in the park and is
one of the oldest living species of trees in the world. Its distinctive fan shaped
leaves were found as fossil remains and the only known fossilized trunk in the
world was also found between the basalt layers, making this discovery very
significant to science.
A good collection of “Ellensburg Blue” and “Petrified Wood” samples
are located at the Kittitas County Museum in downtown Ellensburg in the
Rollinger Rock and Mineral Collection. A wonderful little book called
“Ellensburg Blue,” written by John Prentiss Thomson, can be purchased at the
museum or found in the Ellensburg and Central Washington University
Libraries.
At the end of each of the tours in this guidebook are lists of the available
literature on the particular areas toured. These lists include both technical and
non-technical references available through interlibrary loan or through one of
the local or state libraries. Included are references to videos also available. Most
all of the references are available at either in the Ellensburg Public Library’s
local history section or in the Central Washington University Library.
20
A Field Trip 50,000 Feet beneath Ellensburg
Figure 4. Modified from Jack Powell, 1989
21
A Guided Tour Under Ellensburg
The city of Ellensburg lies in a structural basin (Kittitas Basin) created by
a series of northwest to southeast trending anticlines and synclines. The Kittitas
Valley Basin is the northernmost of six Neogene basins that are located along
the western margin of the Columbia River Basalt Plateau. It is a structurally
complex growth basin developed at the northwestern margin of the Yakima
Fold Belt. The basin is comprised primarily of three geologic units that are
assumed to overlie the older geologic units found in the region (Figure 4).
The oldest unit of the basin itself is a portion of the Columbia River
Basalt Group overlain by the Ellensburg Formation. Deposited on top of the
Ellensburg Formation is the Thorp Gravel and more recent alluvial deposits.
Glacial melt water carried into the basin remnants of the ancient Cascades, and
deposited them in the Ellensburg Formation (5 to 10 million Years old).
Our tour starts with the uppermost geologic layers and works downward
and backward through time (Figure 4). The youngest and uppermost layer is the
Ellensburg Formation, which filled the developing basin to a thickness of about
4000 feet. The Ellensburg Formation includes all sedimentary rocks that
underlie, overlie, or are inter-bedded with the Yakima basalt subgroup of the
Columbia River Basalt Group. When new basalt flows poured out over the
sediments, they were encased within the basalt (Ayers and Bentley, 1996). The
Ellensburg Formation is divided into three stratigraphic units: the upper alluvial
stratum, the upper Ellensburg Formation, and the lower Ellensburg Formation.
The best-exposed section of the upper Ellensburg Formation is Craig's Hill and
is discussed in greater detail in the next section of this guidebook.
The Columbia River Basalt Group is the next layer encountered as we
continue our trip downward into the past. The Grand Ronde Basalt member is
the oldest and most extensive basalt of the Yakima Basalt unit in the Columbia
River Plateau Basalt Group. Within the Kittitas Basin, the Grand Ronde Basalt
consists of 4 to 68 individual flows that range from 82 to 330 feet thick yielding
a local thickness of at least 8200 feet.
The Grande Ronde Basalt Group is the oldest and most extensive group
of flows found in the Yakima Basalt Belt and is the only group found in the
western border of the Columbia Plateau. These groups of basalt flows are
believed to make up at least 85% of the Yakima Basalt Group. Its flows are
described as very fine-grained, black-colored basalt. Most of the flows appear
to be indistinct from one another in the field. Other methods, like chemical and
magnetic analysis, are required to differentiate between the different flows.
Below the Columbia River Basalt lie the Wenatchee Formation (34
million years old), the Roslyn - Chumstick Formations (43 million years old),
22
the Teanaway Formation (49 million years old) and the Swauk Formation (50
million years old). The Wenatchee Formation is one of the more recent
consolidated sedimentary deposits in the area. It overlies two other distinct and
important sedimentary deposits, the Roslyn-Chumstick and the Swauk
Formations.
The Wenatchee Formation was deposited from a northeasterly direction
onto the tilted strata of these older formations. Exposures within the Ellensburg
area are rare, the nearest being in the area of the Swauk Prairie northeast of
Ellensburg. Numerous outcrops are observable closer to Wenatchee. The
sediments within the formation were deposited some 20 million years before the
onset of the Columbia River Basalt, and are believed to have been transported
from a very short distance due to the angular shape of the individual sand
grains. These grains make up the very pure quartz sand that is mined throughout
its location.
The Roslyn - Chumstick formations are discussed in detail in the Cle
Elum - Roslyn section of the guidebook, as is the Swauk Formation in the
Liberty, Red Top, and Swauk section. The next tour is of Craig’s Hill and is an
interesting piece of the Kittitas Valley’s glacial history. The Hill literally tells a
story of what the climate was like, when volcanoes erupted, and what plants and
animals lived here.
Legend: Lithologic symbols used for identification of rocks in the Kittitas
Valley area.
The lithologic pattern symbols like these above are used to distinguish
different rock types of different stratigraphic units. Lithologic means rock type,
and a standard has been set so that everyone can read the symbols and
understand a geologic map, no matter where in the world you are.
23
Figure 4. Stratigraphic column of Craig’s Hill, Modified from Williams, 1991
24
A Guided Tour of Craig’s Hill
The trail leading up Craig’s Hill is found behind the Ellensburg Rodeo
grounds, south of the livestock barns. The trail proceeds to the top of the hill to
the water tower where an overview of the whole Kittitas Valley can be seen.
Craig’s Hill is a deposit of Pleistocene to recent (2 million years ago to
present) loess and sheet-washed deposits that were draped on the steep, eastern
leeward slope of a resistant remnant of the Ellensburg Formation (Figure 4).
These sediments are believed to have been deposited on Craig’s Hill in the last
2 to 10 million years.
Craig’s Hill (Figure 4) is generally considered to be the upper alluvial
portion of the Ellensburg Formation and is about 30 meters (98.43 feet) thick.
Volcanic materials have also been analyzed to provide age dates of the
sediment packages within the Formation.
The loess layers seen on top of the hill are windblown loess, similar to
those found throughout Central Washington. These sediments were eroded from
the Cascade Mountains during the last ice age and are made up of fluvial,
eolian, and volcanic materials. The fine silty sediment was washed out of the
receding glaciers as rock flour, and the wind picked it up and distributed it
throughout the region. These are some of the best sediment layers for
agriculture and responsible for the success of farming in this area.
The Craig's Hill conglomerate is the upper portion of the Ellensburg
Formation. The Kittitas Valley was filled with nearly a mile (4000 feet) of these
sediments over a period of 12 million years. The sediments are layered and
rounded cobbles, pebbles, and sand deposited by the Yakima River.
The air-fall tuff layer found below the Craig’s Hill conglomerate is a onefoot thick layer of volcanic ash believed to be 11-13,000 years old. It is
believed to originate from an eruption of Mt. St. Helen.
The next layer down is a brown-colored mudflow, called a lahar.
Lahars are a mixture of volcanic ash, water, and debris picked up along the way
from an erupting volcano. This lahar layer has small pumice fragments mixed
throughout it.
The next interesting feature is a clastic dike. Clastic means little pieces or
fragments, and dike means that it cut across other preexisting layers. This dike
may have been created as water and sediments were forced upward through the
overlying layers.
The wind blown sand dunes seen in the next layer suggest a period of
drier climate. It is believed that sands of the ancient Yakima River fed these
dunes. When the climate becomes wetter the dunes were stabilized by the
moisture and plants moved in to make them their home. Other dunes and dune
25
fields can be found east of the Columbia River. Four sets of dunes are found
separated by four paleosols in Craig’s Hill. Paleosols (ancient soils), provide a
glimpse of the interglacial climate and environmental conditions of the past.
A thin layer (3 inches) of white clay lies below the dunes and is filled
with leaf fossils. The fine-grained texture of the clay layer tells us that a quiet
and shallow lake deposited them.
The Indian Trail Ash was once thought to be seven to nine million years
old. Recent studies of the ash dates it around five to six million years old
(Lamb, 1997). The ash has many broken mineral pieces that can be seen with a
magnifying glass. It contains blackish-green hornblende, white feldspar and
reddish iron-stained quartz crystals.
The next layer, the Eighth Street Overbank, was deposited just as it
sounds, over the banks of an ancient river. This area was a grassy area that
occasionally flooded as climate conditions got wetter.
The Eighth Street Conglomerate is the largest of all the rock units located
in Craig’s Hill. It was deposited by a river over a long period of time and
consists mostly of rounded gravel. The rounded gravel helps to identify it as a
river deposit in which the rocks were repeatedly moved, tumbled and banged
against each other until they became rounded. Several sand lenses can be found
throughout this section that are thought to be sand bars that formed as the river
migrated along its path.
The Fifth Street Overbank formed very much like the Eighth Street
Overbank and over lies the Fifth Street Conglomerate. It is thought to be about
nine million years old. Fossil teeth of a three-toed horse, camels, shovel tusk
elephants, and rhinoceroses that roamed this area during this time can be found
throughout this deposit.
A great view of the whole valley can be seen from the top of Craig’s Hill.
See the Figure 5 below for an overview of the geology related to the panoramic
view seen from this location.
Figure 5. Overview of the Geology of Kittitas Valley.
Literature on Ellensburg and Craig's Hill
26
Ayers, Angela M. and Robert D. Bentley, 1996. “Structural and Stratigraphic
Control of the Hydrology of the Kittitas Basin”. Unpublished
Manuscript. McNair Scholars Program Summer Research Internship.
Bentley, Robert D. and Newell P. Campbell, 1983. Geologic Map of the
Ellensburg Quadrangle, Washington. Washington State Department of
Natural Resources.
Lamb, Jodie, 1997. “Quaternary Stratigraphy of the Kittitas Valley, with
Emphasis on the Craig’s Hill Section.” Senior Thesis, Central
Washington University Geology Department Library.
Mason, Charles L., 1996. The Geological History of the Wenatchee Valley and
Adjacent Vicinity. Gig Harbor: Gig Harbor Press.
Powell, Jack, 1997. “Fieldtrip 50,000 feet beneath Ellensburg”. Department of
Natural Resources. Unpublished Illustration.
Waitt, Richard B., Jr., 1979. “Late Cenozoic Deposits, Landforms, Stratigraphy,
and Tectonism in Kittitas Valley, Washington.” Geological Survey
Professional Paper 1127. p. 18.
Williams, Mike, 1991. “Stratigraphic column of Craig's Hill.” Unpublished
Illustration. Central Washington University.
27
Where Does Ellensburg’s Water Come From?
The city of Ellensburg has seven water source wells. Six are located in
town and one is located outside of town by the Yakima River. Five of the city
wells are deep wells (300 to 1200 feet deep) and are located at Kiwanis Park,
south of Mt. Stuart, east of the rodeo grounds, Memorial Park, and Whitney
Park. Central Washington University owns the last well.
Our drinking water is drawn from the Ellensburg Formation, which fills
the basin we live in. The Ellensburg Formation is made up of layer after layer
of rock, sand, and gravel that accumulated to a depth of about 4000 feet. This
accumulation occurred over a period of 2 to 10 million years. Craig’s Hill,
discussed on pages 24-26 and shown in Figure 4 is considered the uppermost
portion of the Ellensburg Formation.
The water stored in the Ellensburg Formation comes primarily from
snowmelt. Snow accumulating on the mountains during the winter is stored
until spring when it begins to melt and drain down the eastern slopes of the
Cascade Range. It flows freely both on top of the ground and underground until
trapped in a basin or reservoir.
Figure 6. Ellensburg Basin Modified from Kennison and Sceva, 1963
28
Water, Our Most Precious Natural Resource
The endless movement of water between the atmosphere, the ocean, and
the land is called the water cycle. About 97% of the earth’s water is in the
ocean, and 2% is frozen and stored in the world’s glaciers and ice sheets. Only
1% of the earth’s water is found in rivers, streams, lakes, and underground.
Conserving water becomes more important as we move into the future
and our water demand grows as our population grows. All life forms need water
to survive, so managing our water resources require that we remember the
needs of the plants and animals we share it with.
Reducing water wastes in our homes and in agricultural practices in our
region will help to preserve this resource and all the life it supports for future
generations. We are fortunate to have more water than most regions, and may
take for granted that we have an endless supply. Losing this precious resource
through waste or pollution would alter our quality of life forever.
For more information on Kittitas County Water Resources these
professionals and programs are available to residents:
• Master Watershed Steward Program
Washington State University Cooperative Extension
• Experiencing Water Resources
A Curriculum & Field Trip for 3rd, 4th, & 5th Grade Students
Kittitas County Extension Agent - Lana Thomas Cruse
207 West Tacoma Street, Ellensburg, WA 98926
(509) 962-7507
• Ellensburg Water and Sewer Operations
Supervisor - Rick Bollinger (509) 962-7133
• Ellensburg Waste Water Treatment Plant
Plant Manager - Erma Grogan (509) 962-7277
• Water Lab, Central Washington University
Science Building, Room 234
Director, Arlene Carter (509) 963-3013
29
Map 2. Yakima Canyon Tour
30
Yakima Canyon Guided Tour
The Yakima River Canyon is a place enjoyed year-round for camping,
hiking, bird watching, fishing, and rafting. Its 9000 acres are managed by the
Bureau of Land Management, to maintain its natural, scenic, and cultural
qualities and to provide a variety of recreational experiences to a variety of
people. Map 2 provides an overview of the features discussed on this tour.
The canyon is rich with plants and wildlife, and there are numerous
occasions to view bighorn sheep, black-tailed deer, and an abundance of bird
species. Special areas for viewing specific plants and animals will be pointed
out along the tour route. Because of the richness of life in the canyon it was
popular long before the arrival of Europeans to this region.
Native American Indians were probably the first peoples to use the
resources of the canyon. They fished, hunted, and collected the seasonal plants
for food. The landscape provided many plants like bitterroot, lomatium,
currents, and camas. The river supplied freshwater mussels and salmon, as well
as larger animals like deer, elk, and bighorn sheep that came to drink.
Later, around the 1840s, Christian missionaries and European Americans
began settling in the area. There were fur trappers, miners, farmers, and sheep
and cattle ranchers. The Northern Pacific Railroad was built in the 1880s and
helped to develop the areas north of Yakima as railroad substations were built at
Roza Creek, Wymer, and Umptanum to service the trains and rail lines.
The unique geological features brought in scientists who studied, and are
still studying, the basalt lava flows that are the predominant features in the
canyon. It is the geologic features that are the focus of this tour, but references
to the plants and animals are included throughout the text, as they are an
important aspect of the special nature of this place.
Please respect that this is their home and you are a visitor to it. The more
people in the canyon the fewer animals there are to be seen, but evidence of
them can be found everywhere if you look closely. Finding an out-of-the-way
location and sitting quietly for awhile may bring the animals back into your
vicinity area.
The topography of this landscape in the past was very different than seen
today. This area was a broad rolling plain on which the river deposited its
sediments and onto which the Columbia River Basalt (CRB) lava flowed. This
canyon was formed at a time of active tectonics.
As you enter the Yakima Canyon from Ellensburg, going south on
Highway 821, notice the stair-step features to the east and west of the canyon
entrance. These “stair steps” are river terraces and they record a history of
changes in the environment of this landscape through time. As the land was
31
physically lifted and deformed by regional plate tectonics, the river continued to
flow, cutting its path through millions of years of Columbia River Basalt (CRB)
rocks. As a result of these two processes the river has become confined, or
entrenched, and has cut a meandering path through the valley leaving the river
terraces as evidence.
The terraces are made up of basalt layers then scattered river gravels
were deposited on top of the basalt layers. Some scientists believe there are as
many as 6 to 8 different terraces throughout the valley.
SET ODOMETER ON (0.0) AT DEPARTMENT OF FISH AND
WILDLIFE SIGN “ENTERING THE YAKIMA CANYON.”
Mile
The area you are driving through from the beginning of the tour
0.0 through the next point is where the river cuts through Manastash Ridge
to
(Figure 7). This ridge is the first of three anticlines that the Yakima River
0.3 cuts through. The Yakima Canyon anticlines were created through
regional plate tectonics by the folding of the rocks making up the
landscape. Anticlines are up-folds or ridges, and synclines are the downfolded areas located between the anticlines.
Figure 7. Anticlines and synclines in the Yakima Canyon
Modified from Diery 1967
Stop 1
On the west (right) side of the river toward the top of the ridge is a
0.6 bumpy area with pine trees growing on top. Geologists describe this type
32
of landscape feature as hummocks. Hummocky topography is evidence
of a large landslide in the past. These types of landslides involve water,
usually in the form of rain. Once the hillside is saturated with water, the
sediment layers become heavy and gravity pulls them down the slope.
Landslides of the same age can suggest much wetter environmental
conditions. Throughout the canyon evidence of both past and recent
landslides can be seen.
Directly across the road is the first observable outcrop of the Ellensburg
Formation (Figure 8). Its distinctive light color distinguishes it throughout the
Canyon and appears frequently. This particular section is a portion called the
Vantage member, it is a sandstone rock unit.
Figure 8. Vantage member of the Ellensburg Formation in the Yakima Canyon
Paleosols (ancient soils) found between the different layers of sediments
and lava provide a glimpse of the climate and environmental conditions of the
past 2 to 20 million years. From this point on the most prominent features in the
canyon are of the Columbia River Basalt (CRB).
The CRB erupted sporadically between 17 up to 6 million years ago,
across the central Washington area (Figure 1). The lava erupted as hot syrupy
flows from cracks in the earth called fissures. These flows would pool up into
lakes then flow out onto the landscape in layers as thick as 500 feet. The CRB
are thought to be made up of as many as 120 individual flows. The cooling
process of the lava created the columns seen at a later stop along this tour.
Mile
33
1.0
As you drive into the first big curve at approximately 1 mile the
most prominent feature is the bowl shaped topography on the east side
(left) of the road. This feature is an ancient meander curve abandoned as
the landscape rose due to tectonics. The river was forced by gravity down
the slope of the rising landscape toward its lowest and present position.
The soils in this area are made up of sandy river alluvium and the area is
now being utilized for agriculture and the beginnings of a new orchard
can be seen.
Mile
At this point an exposure of a section of sand and gravel
2.0 stratigraphy can be seen and gives the viewer a glimpse of the layering of
river materials. The different layers are distinguished by changes in the
size, type, or color of the particles found in the individual layers. It is not
always easy to distinguish between the layers and this is where
specialized training is required. The study of rock or sediment layering is
called stratigraphy.
The area between two different layers is called a contact. This contact
point represents changes in rock or sediment type. A change in layers suggests
changes in the environment or processes in which the materials were deposited.
In sedimentary layers the larger particles need greater energy to be moved, so
observing larger particles suggests that more or faster water was available to
transport the sediments Further study is required to determine the causes for
more water in this environment.
The next big curve to the west is called “Beaver Tail” (Figure 9). It is a
255-degree turn in the river. This formation is a classic meander curve created
by gravity forcing the river to take the least resistant path as the anticlines rose
in response to plate tectonics.
Mile
The first good exposure of the basalt lava flows can seen. On
2.2 the west side of the river a small alluvial fan has formed as the result of
sediments being washed out of the higher areas downward toward the
river. When the water and sediments reach their lowest point they are
spread out in a fan shape as their tributary stream wanders across the
landscape.
The area along the riverbank is called the riparian area. It is lush with
vegetation and animal life. Along the banks of the river can be found the tracks
of animals that come to drink. Mule dear inhabit this area and above year round.
34
Elk also use this area in the winter months. On the cliffs above, California
bighorn sheep can be seen feeding among the rocky cliffs.
The Yakima River Canyon is also a haven for birds. The canyon has one
of Washington State’s highest concentrations of nesting birds of prey. Raptors,
as they are called, use the canyon for nesting and breeding. Ten different
species of raptors can be found depending on the season; golden and bald
eagles, red-tailed hawks, prairie falcons, and American kestrels can be viewed
fishing from the river.
Mile
On the western side of the river, along the route to the next point
2.6
of interest, runs the Northern Pacific Rail line completed in the 1880s.
This rail line has an interesting history, depicted in a book called
Gateway to Time referenced to at the end of this chapter. From this point
and for the next four miles, Bighorn sheep can be seen scattered on the
higher slopes and ridges.
Mile
As you proceed through the canyon from this area the evidence of
3.0 small landslides can be seen. Throughout the canyon, landslides cause
significant changes in the topography. Several large debris flows
occurred in June of 1998 (Figures 9 & 10) that covered the road and
closed the canyon for about a month.
Mile
Figure 9. Beaver Tail meander and debris flows
The largest landslides resulting form the June 1998 rainfall
35
4.2
to
6.7
occurred in the next area for about 2.5 miles. These debris flows (Figure
10) closed the road and diverted the river. Three new debris fans were
created into the river by the landslides, and are making popular new
fishing spots.
Figure 10. Debris fans created by intense rainfall June 1998
Debris flows are gravity caused rapid mass movements of water saturated
loose sediments and soil lying on steep slopes. The sediments include a variety
of sizes from, soil to boulders that mixed with water and flow together. This
mass of material scoured the channel in which it flowed and picked up and
carried everything along its path, including trees.
The walls of the channel now expose the layering of the material
blanketing the hill slope. The channels and walls are interesting to look at, but
can be dangerous places to be, particularly during rainy times. The layers in the
walls of these channels are highly erodible, and falling rocks should be
expected. The Department of Transportation has fenced off the entrances to the
debris channels to protect people from entering or being harmed in one of them.
36
The first exposures of basalt columns can be seen along the eastern side
of the road. At the next stop the colonnade structure can be viewed up close.
The colonnade (Figure 11) is the result of fractures created in the lava flow as it
cooled form the bottom of the lava flow to the top. The individual columns have
a hexagonal shape and a single column can weigh up to several tons.
Figure 11 Whiskey Dick basalt flow colonnade
Stop 2
Mile
Around the curve, where the guardrail ends is a wide pull-off point
7.1 on the right, with parking available. The basalt flow (Figure 11) in this
picture can be seen directly across the highway from the guardrail. In the
figure below (left) the Whisky Dick basalt lava flow is located at the
bottom.
Figure 12. The illustrations above show the different basalt flows (left) and the
idealized structure of a basalt flow (right), Modified from Powell, 1989.
37
The illustrations in Figure 12 on the previous page show the relationships
of the individual flows to the river (left), and how an idealized individual lava
flow cools into a single layer consisting of several different flow structures. As
basalt lava cools it crystallizes (turns into solid rock). The crystals referred to
are microscopic and require specialized equipment to see. Petrology is the
specialized science of rock structure and petrography is the microscopic study
of rocks in thin section.
As basalt cools it shrinks and cracks, much like mud does when it dries.
The lava cools from both the bottom and top of the flow and has two distinct
structures within a single flow. The two distinct structures created are the
colonnade (on bottom) and the entablature (on top).
At the base of the lava flow (Figure 12 right), is a series of sediments,
palagonite and pillow basalt. The sediment layer is the one the lava flowed
onto. The palagonite is created when lava flows onto or into moist sand or soil.
The pillows are formed when lava flows into water. These features help
scientists distinguish the base of an individual flow. The lava flows in this
region were deposited intermittently over the course of about 10 million years.
The next features seen are related to the cooling that occurs within an
individual flow. A general pattern consisting of sediment, pillows and
palagonite, colonnade, entablature, and vesicular features help to identify
individual flows from each other in the over 120 individual flows found in this
region.
Colonnade structures can have two jointing patterns; as blocky jointed
columns as seen here and in Figure 12, or as platy jointed columns seen
throughout the canyon within its walls. The platy jointing looks just like it
sounds like plates stacked on top of each other into tall columns.
Entablature structures can have two jointing patterns also, as interconnected fans or as hackly pieces. The fans have a similar appearance to the
colonnades, but the hackly pattern looks like thousands of small pieces put
together. At the top of the entablature structure is an area of vesicular basalt.
This is the top of the flow where gasses trapped in the lava have risen to the top
of the flow creating the bubbles (empty spaces) in the solid rock.
Mile
Umtanum Creek is on the right and is a popular hiking spot in the
8.4 Yakima Canyon. A footbridge crosses the Yakima River into an area
where numerous opportunities exist to view the wildlife and wildflowers
of the canyon. A book called the Natural History of the Wenas Area:
The Trailside Series, by the Seattle Audubon Society 1986, is out of print
but available at the Ellensburg Public Library and is a good reference to
the plants and wildlife in this area.
38
Mile
Around the next bend to the east (left) you enter a bowl shaped
8.5 amphitheater like feature created by the changing position of the river as,
to
tectonics caused the landscape to rise. In the top of Figure 13 the contour
10.0 lines on the map show how steep the walls of this abandoned meander
are and how the slope decreases at the base of the feature along the road.
Mile
At the end of the next curve, on the west side (right) of the river, is
10.2 a large alluvial fan depicted in the bottom center of Figure 13. It’s broad
to
fan is the result of several small tributary streams in the higher areas
10.4 coming together into one stream that delivers all the eroded sediment
onto this wide area in the river channel. The contour lines on the map are
further apart and show a gentle slope.
Figure 13. Abandoned meander and alluvial fan features
Mile
At about this point the road passes through a basalt flow. This area
10.8 is made up of the hackly entablature structure pattern discussed earlier
and is subject to falling pieces from this flow. As you come out of the
flow you can see in the distance ahead a white strip in the hillside on the
opposite side of the river. The next stop is at the Beck Memorial.
39
Stop 3
The Beck Memorial & BLM Lmuma Creek Recreation Site
Mile
This stop discusses a number of topics and geologic features.
12.2
Feature 1. The Beck Memorial was built in honor of Central Washington
College, now Central Washington University, geology professor George Beck.
This memorial was built in honor of his life’s work, as an educator and
scientist, and to his commitment to preserving the history and resources of this
region. It was dedicated October 6th 1969. George Beck earned his Bachelor of
Science degree at Washington State College, his Master of Science degree at
the University of Washington, and did graduate work at the University of
California at Berkley. He taught high school, college, and after retirement as
served as curator of the Yakima Museum.
Prior to his position at Central George Beck taught high school physics
and music at Lower Naches, Warden, and Ephrata and also served as principal
of Ephrata High School. Beck came to Central in 1925 as an instructor of music
and science. He was also a member of the Yakima Symphony and the State
Parks Commission.
He taught geology and paleobotany at Central from 1933 through 1959
and distinguished himself worldwide in this position. His primary research
focus was the study of the lava Petrified Forest of the Columbia Basin. He is
credited with the discovery of seven petrified ginkgo trees, the only specimens
of this type known to exist. His study interests also related to the excavation of
the fossil remains of elephants, rhinoceros, camels, buffalo, lions, and horses
found in Washington. All of his research was conducted with the help of
undergraduate students at Central.
He was the author of numerous articles in journals and magazines many
listed in the literature section of the Ginkgo Tour of this book. He was the
driving force and founder of the Ginkgo National Monument, now the Ginkgo
Petrified Forest State Park located 1.25 miles north of Vantage, Washington.
Feature 2. The white-colored stripe in the canyon wall across the river from the
Beck Memorial is the ash from an eruption of Mt. Mazama in southern Oregon.
The Yakima River had probably already cut through the CRB to about this level
when the Mazama eruption occurred. The ash layer was deposited on top of a
terrace and then covered with river sediment. Since the underlying bedrock is
deformed from tectonics, but the ash layer is still horizontal and not deformed,
the Mt. Mazama eruption had to have occurred after the major tectonic changes
to the canyon.
The eruption of Mt. Mazama about 6900 years ago was so enormous that
it exploded and blew away 2500 feet of its top. Volcanic ash was blown
40
northward across our region and all the way into Saskatchewan, Canada. The
ash in this location is about one foot thick. This ash has a distinct chemistry and
scientists use this it to date stratigraphy all over the western portions of North
America. Only a caldera, named Crater Lake and a cinder cone called Wizard
Island remains today where Mt. Mazama once stood.
Feature 3. Mt. Baldy and located behind you to the southeast and depicted
below in Figure 14, is the crest of the Umtanum anticline and is 3255 feet high.
The most prominent feature on Mt. Baldy is the overturned Umtanum anticline.
The layer of basalt flow seen to curve into the road on the left side of Mt. Baldy
is the Wymer flow. Two faults occur on either side of this flow and are called
the Wymer Fault (north side) and the Burbank Fault (south side). The dotted
areas in the illustration below (Figure 14) have been eroded away and the solid
lines depict the mountain as you see it today.
Figure 14. Mt. Baldy and the Umtanum anticline from the Beck
Memorial, Drawn by Jack Powell, 1989.
Mile
As you continue down the road, on the left side of the road, is
12.6 another light-colored stripe within the sediment layers. This layer is made
up of the Vantage sediments as depicted in the bottom left corner of
Figure 14. From this area to the next feature at the Rosa Recreation Site
at mile 17 the ridges across the river are a good place to spot wildlife.
This area is known for small herds of deer.
Mile BLM Rosa Recreation Site
17.1
This area is located upstream from the Rosa Dam and is a popular
spot for ending float trips on the river. It is also a good spot to view the
birds of the Yakima Canyon, especially the Great Blue Heron that nests
in the wetlands located just down stream from here. The Rosa Dam slows
the water in this area, and as the finer sediments settle out of the river
41
water, a sand bar has been created. The sand bar has become the home of
numerous plants that have created a wetland habitat area. Many birds and
animals have moved into the wetland and made it home. Early in the
morning and late in the evening a variety of species of birds can be heard,
and viewed hunting their meals.
Mile Rosa Dam
18.4
The Rosa Dam was completed in 1939 and was created to divert
water into the Rosa Canal. The canal supplies water to the Yakima
Valley’s irrigation system that supports its many agriculture interests.
Orchards are an important part of the economy of this region and
particularly to the city of Yakima. Cherries, apples, pears, peaches,
apricots, and grapes are a few of the varieties of fruit grown in the
Yakima Valley.
Mile 20.1 Kittitas – Yakima County Line
Along the rest of the tour the hill slopes to the east (left) of the road are
covered with talus. Talus is an accumulation of broken rock at the base of a
cliff. This material gathers in piles in front of a cliff face until something
disturbs it or gravity causes it to move down the slope. Talus can sometimes
become incorporated into landslides and debris flow. In many of the layers
along this part of the road large angular rock fragments can be seen “floating”
alone in a layer of muddy sediment. The angular shape to theses rocks tell
scientists they were not river deposited sediments, but probably picked up in a
debris flow.
At mile 21 the old canyon road route took a higher road to the left. This
older road went through a tunnel, at mile 21.5, that was drilled into the Rosa
flow basalt layer. The tunnel has become unsafe due to falling rock fragments,
and is closed to the public. At about the tunnel site the view ahead opens up
and on clear days Mt. Adams can be seen directly in front of you.
Stop 4
End of Canyon Tour and Turn Around Point
Mile
22.3
Turn left off of State Route 821 into the second entrance of the
road area paralleling 821. Parking is allowed here and this is a good place
to view Selah Butte, depicted in Figure 15 on the next page. You are now
stopped in the Selah Gap and its formation is somewhat of a mystery.
42
Figure 15. Selah Butte, illustration by Jack Powell 1989
Scientists have not determined how an opening this large was created in
this area, although they are sure that the ancient Yakima River played a
significant role in its creation. This area is called a water gap. Water gaps are
a type of bottleneck where water backed up and was forced through a smaller
opening. This bottlenecking gave the water coming out of the other side
greater erosive power and probably scoured out the area seen today. The
effect is similar to the one created when a portion of a garden hose is blocked
off and a stronger stream of water is created.
From this location the layers on either side of the road can be mentally
matched-up. The top layer of basalt on either side of the road is the Pomona
Flow of the CRB. The effect is much like cutting and removing a piece from a
layer cake. Although the piece is gone the layers on either side still match up.
This area also has a rich archeological history as discussed in a book by
Claude Warren (1968) called, The View from Wenas: A Study in Plateau
Prehistory. It documents a number of artifacts dated to thousands of years old.
43
Literature and References on the Yakima Canyon
Bentley, Robert D. and Newell P. Campbell, 1983. “Geologic map of the
Yakima quadrangle, Washington.” Washington State Department of
Natural Resources.
Bureau of Land Management, 1997. “Yakima River Canyon Map.” United
States Department of the Interior.
Stepniewski, A. 1980. “Birds of the Yakima River Canyon.” Bureau of Land
Management. Wenatchee, Washington.
Campbell, Newell P., 1981. Geology of the Yakima Area. Published by the
Author. 64 p.
Campbell, Newell P., 1975. “A Geologic Road Log Over Chinook, White
Pass, and Ellensburg to Yakima Highways.” Washington State
Department of Natural Resources Information Circular 54, 82p.
Diery, Hassan D., 1967. “Stratigraphy and Structure of Yakima Canyon
Between Rosa Gap and Kittitas Valley, Central Washington.” Masters
Thesis. University of Washington.
Hines, Donald M., 1992. Ghost Voices: Yakima Indian Myths, Legends,
Humor, and Hunting Stories. Issaquah: Great Eagle Press.
Mackin, J. Hoover, 1961. “A Stratigraphic Section in the Yakima Basalt and
the Ellensburg Formation in south central Washington. Washington State
Division of Mines and Geology.” Report of Investigations No. 19.
McCulloch, Mac, 1990. Gateway to Time: Mile by Mile Guide to the Yakima
Canyon. Yakima: Shields Printing.
Monk, G. 1976. “Raptors of the Yakima Canyon.” Department of the Interior,
Bureau of Land Management.
Warren, Claude N., 1969. The View from Wenas: A Study in Plateau History.
Pocatello: Idaho Museum of Natural History.
44
Map 3. Lookout Mountain Circle – Glacial Features
The Thorp -Teanaway Glacial Features Guided Tour
The North Cascades of Washington extend from Snoqualmie Pass to the
Canadian Border and contain 750 glaciers. The North Cascade Range separates
the state into two separate climatic regions. The glaciers associated with the
features in Kittitas County flowed down three main drainages (rivers) of the
eastern slopes of the North Cascade Range. These drainage areas occupied the
areas of Keechelus, Kachess, and Cle Elum Lakes.
Five stages of alpine glaciation are identified as originating on the high
peaks of the Cascade Crest. The physical evidences of these five glacial stages
remains today and are represented by landscape features of terminal moraines,
graded outwash terraces, and correlating stratigraphic sequences.
45
Figure 16. Glaciers and their extension into Kittitas County, Modified from
Porter, 1969
The illustration above (Figure 16) depicts the positions of glaciers that
created the features seen on the landscape today. Glaciers created and occupied
the basins of lakes Keechelus, Kachess, and Cle Elum and flowed down the
river valleys of the Yakima and Cle Elum Rivers.
The glaciation of this region that occurred during the geologic time
period called the Pleistocene, from about 2 million years ago to 500 years ago.
When the climate of the region became colder the ice accumulated on the peaks
of the Cascades and flowed down the eastern slopes toward the Kittitas Valley.
When the climate warmed the glaciers receded back toward the Cascade crest,
but left outwash deposits and evidence of their existence and positions
throughout the region.
The sharp features seen on the high cascade peeks are cirques, horns,
arêtes, and hanging valleys. The evidence found along the glaciers’ lower routes
are U-shaped valleys, basin lakes, and striations in the bedrock. The sediments
associated with the glaciers are called moraines, eratics, till, outwash, and loess.
Scientists use techniques like pollen analysis, carbon dating, radiometric
dating, and weathering and erosional features to determine the age and
relationships between different glacial events in the region. A technique
developed by University of Washington professor Stephen Porter was to
measure weathering rinds.
Weathering rinds are concentric bands of oxidized minerals found in the
basalt rocks moved by the glaciers. The wider the band of oxidation, the older
the sample rock is. When compared to other basalt samples, found on different
glacial moraines, a relative age date can be given to determine when the glacier
placed the rock.
This tour of the glacial features circles the area around Lookout
Mountain. The tour begins outside Ellensburg on the canyon road to Cle Elum,
State Route 10. The tour begins at the Wenatchee turn-off sign at U. S. Route
46
97 then proceeds toward Cle Elum to the northwest on State route 10 to the
junction at State Route 970. At the 970 and 10 junction the tour turns (right)
back to the northeast until meeting up at the north junction of U. S. Route 97 at
Virden, which takes you back to south toward Ellensburg.
SET ODOMETER AT 0.0 AT THE JUNTION OF STATE ROUTE 10 and
U.S. ROUTE N97 (THE TURN-OFF TO WENATCHEE)
Mile
As you enter this section of the tour there are numerous
0.0 features to be seen but very few safe parking areas. Where pull-off points
are available a number of features will be pointed out. The first features
are the “Thorp Gravels” seen on the right hand side (north) of S.R. 10.
These are the same gravels found in Craig's Hill in Ellensburg and
discussed in the Craig’s Hill tour. Good exposures of these gravel
deposits are visible from about mile point 0.6, after you pass under the
railroad trestle, to mile 3.7 to the first parking area located on the left side
of the road.
This gravel formation is constantly changing and has been for hundreds
of years. If you look along the face of the ridge there is evidence of older slides,
along a similar surface area. The older slumps are now re-vegetated and the
ages of the trees help to determine when the slump occurred. The whole area
was cut into by the Yakima River and exposed both the “Thorp Gravels” and a
portion of the Ellensburg Formation.
Mile
The largest slump occurred in June of 1970 when a portion of the
3.2 road was closed due to the massive amount of gravel covering the area.
The mass of gravel blocked the Yakima River for a time and fishermen in
the river witnessed the river “drying up” down stream of the blockage.
This portion of the road was re-built on-top-of the landslide, as the costs
to remove the gravel exceeded the costs to build a new road.
Stop 1
Mile
The first stop is located ahead on the left side of the road. Here the
3.7 ”Thorp Gravels,” Figure 17, are exposed best. They are believed to be
between 3 and 4 million years old and were name after of the community
of Thorp. The whole structure is made up of individually layered beds
made of gravel and sand. It is not well consolidated, continually
weathers, and is prone to continuing erosion and landslides.
47
Figure 17. “Thorp Gravels” along the north side of State Route 10
This whole area has experienced the giant landslides called ‘slumps.’
Slumps are the result of the gravels being saturated by water, primarily from
irrigation run-off. The water enters the gravel formation and percolates through
it causing the whole formation to erode very quickly. The water can often be
seen on the cliff face where it seeps out and discolors the surface.
Figure 18. Ellensburg Formation along the north side of State Route 10
STOP 2
Mile
The exposure of the Ellensburg Formation at this location, above,
5.7 is one of the most interesting to geologists. The exposure here is the
middle portion of the Ellensburg Formation, overlain by the “Thorp
Gravels.” This exposure is made up of sandstones, sitlstones,
conglomerates, and thick layers of volcanic ash called lahars.
The lower portion is made up of sandstones, mud, volcanic mud flows
(lahars) and small packets of gravel. The features on the surface are made by
the weathering of the surface by wind and water. This area too is continually
48
eroding away, and rocks continuously fall from above. A hard hat is a good idea
if you plan to approach the area for a closer look.
From this area on, the most predominant features on the landscape are the
terraces located primarily on the south side of the river. The diagram below
Figure 19, from Porter 1976, shows the relationships of the different terraces in
the upper Yakima River Canyon to the location of the river today. Shown in this
diagram are the loess and soils developed on top of the glacial outwash.
Figure 19. Glacial Terraces along the Yakima River, Modified from Porter,
1976
Mile
The tour continues by driving onto the top of the Thorp Drift.
6.5 From this stopping point, and for the next half-mile, the road grade
steepens. The elevation change is due to the incline onto the terminal
moraine that marks the furthest advance of the Thorp Glacial stage.
The area ahead is rich with wildlife. Bald Eagles and Osprey make this
area their home. Watch for Eagle nests and pairs of birds fishing for dinner in
the Yakima River. This area is also a crossing point for deer and elk and they
can often be seen at dawn and dusk heading to the river for a drink.
49
The Thorp highway is on your left at 7.2 miles. The next stop is just ahead
on the right side of the road at 7.8 miles, and provides a good view of five
terrace levels.
Stop 3
Mile
This point provides a good safe place to pull off of the road and
7.8 view the terraces numbered in Figure 20 below. Use the picture below
to find the terrace levels. Some people believe there are actually more
terraces. Do you see more? See if you match up the terraces on either
side of the river?
Figure 20. Terraces in the upper Yakima Canyon
Mile
As the tour continues you enter an area where the road parallels
8.2 a basalt flow on the right. This area is notorious for falling rock that is
being weathered by water flowing through the cracks. In the winter
months this cliff face is covered with frozen waterfalls.
A number of homes can be seen at different levels along the opposite
side of the river. The position of these homes also indicates the different
terrace levels found in the canyon. On the right hand side of the road you
pass at mile 9.0 a deep canyon carved by Swauk Creek whose headwaters
are at Blewett Pass to the north. As you drive up the incline there is another
pull-off point on the right where some columnar basalt structures can be
seen. This is a popular rock gathering spot, but is called “Rattlesnake Rocks”
by the locals. Up ahead is a flat area called “Bristol Flats” it was once a
50
railroad substation. The field areas on the right are part of the Thorp Prairie
deposits this name was given to all of the deposits delivered by the Thorp
glacial episode. The next stop is ahead on the left side of the road. There is a
good pull off point at 14. 2 miles and an interesting set of rock units is a
short walk up the road.
Stop 4
Mile
The rock units at this stop are pictured below in Figure 21 and
14.2 are located about 500 feet up the road on the right side of the road.
Two rock units can be seen with a very good example of a contact
between them. The top unit is a conglomerate. These rounded stones
were delivered by water and are poorly cemented. The bottom unit is
a mudflow. The vertical crack seen in the center of the picture was cut
by water and caused the whole left side of the hill to be off set from
the right side. The shift downward was caused by water saturation and
slumping that affects most of the sediments along this route.
Figure 21. Conglomerate and Mudflow Rock Units
At mile 15 Mt. Stuart can be seen in the distance to the north
and its sharp features are cirques, horns, and arêtes. Cirques form as
the result of glacial carving and the weathering and erosion of the
rocks above the surface of the ice. This process is called frost wedging
and it creates a bowl-like depression in the mountain. Snow
accumulates in the bowl and becomes compacted by its own weight
and is converted into a glacier. As the process is repeated the glacier
51
spills over the edge of the cirque and the glacier flows downward due
to its own weight. Horns are features that result from cirques being
formed on several sides of a mountain. Arêtes are the sharp ridges
formed in-between and separating the cirque basins. They are created
by the expansion of ice in the cracks of the rocks a process called frost
wedging.
Junction 970
The turn-off to the next part of this tour is ahead at the
Mile 16.2 junction of State Routes 10 and 970 . Take a right turn onto
State Route 970 toward the northeast to Wenatchee. This road
runs between Lookout Mountain on the south (right) and the
end of the Cle Elum Ridge on the north (left) to the Teanaway
River. The east end of the Cle Elum Ridge is sandstone
blanketed with glacial debris. The Teanaway River Bridge is at
19.9 miles where the view opens onto the Swauk Prairie at mile
22.
Stop 5
Mile
22.3
The pull-off point is on the right side of the road. This
area
provides an overview of the whole Swauk Prairie and a look at
a glacial erratic. The Swauk Prairie is believed to be a middle
Pleistocene moraine complex at least half a million years old,
but its age has not been exactly determined. The topography of
this gently rolling moraine surface is covered with loess that
has been extensively farmed for decades.
The bolder sitting on the opposite side of the wire
barricade is an erratic. This boulder was transported by the
glacial ice and dropped at this spot when it became too heavy
for the retreating ice to carry. Its rock type is like no other in the
area and could only have been carried in from an area much
further north.
The tour turns back to the south (right) at mile 24 onto U.S. Route 97
at Virden. The road inclines onto what is believed to be a lateral moraine
created by the retreat of glacial ice that occupied the classic U-shaped valley
seen on the right side of the road. At the top of the hill at mile point 26.9 is a
sand, gravel, and rock-mining operation owned by Ellensburg Cement
Products. This operation is closed to the public but there is a pull off point
52
and road cut that exposes the moraine deposits. Glacial deposits are good
resources for different sizes of gravel used for mixing concrete, general
construction and road building projects. Special machinery sorts the sand
and gravel into uniform sizes that are sold commercially.
Literature on the Kittitas Valley Glacial Features
Bush, T. A. and E. S. Cheney, 1996. “Guide to the Geology in the Vicinity
of
Swauk and Snoqualmie Passes Central Cascade Mountains,
Washington. Northwest Geological Society Guidebook 12.”
Hubley, R. C., 1956. Glaciers of the Washington Cascade and Olympic
Mountains: Their Present Activity and its Relation to Local Climate
Trends. Journal of Glaciology, V. 2 No. 19, p. 699-674.
Pelto, M. A., 1991. “North Cascade glaciers: their recent behavior. North
Cascade Glacier Climate Report.” Foundation for Glacier and
Environmental Research, Moscow, Idaho.
Porter, S. C. and T.W. Swanson, 1997. “Cosmogenic Isotope Ages of
Moraines in the Southeastern North Cascade Range”. Pacific Northwest
Friends
of the Pleistocene Field Excursion. pp. 19.
Porter, Stephen C., 1976. Pleistocene Glaciation in the Southern part of the
North Cascade Range, Washington. Geological Society of America
Bulletin, V. 87, p 61-75.
____________. 1975. Weathering rinds as relative-age criterion: application
to
subdivision of glacial deposits in the Cascade Range. Geology V. 3
No. 3 p 101 - 104.
____________. 1969. “Pleistocene geology of the east-central Cascade
Range,
Washington.” Guidebook for the Third Pacific Coast Friends of the
Pleistocene Field Conference, pp.54.
53
Post, A., Richardson, D., Tangborn, W., and F. L. Rosselot, 1971. Inventory
of
glaciers in the North Cascades, Washington. Geological Society of
America Professional Paper 705 - A. pp. 26.
Waitt, R. B., 1977. “Guidebook to Quaternary Geology of the Columbia,
Wenatchee, Peshastin, and Upper Yakima Valleys, West-Central
Washington.” Geological Society of America 1977 Annual Meeting,
Field Trip No.13. United States Geological Survey. Open File Report
77-753.
Map 4. Liberty, Red Top, Swauk, and Blewett Pass
An Overview Tour of the Liberty, Red Top,
Swauk and Blewett Areas
The tour along this route begins at Virden, Washington that is the
junction of State Route 970 and U.S. Route 97. Virden is located
approximately 13 miles northwest of Ellensburg on U.S. Route N97 from the
54
turn off for U.S. N97 located at the junction of State Route 10 on the canyon
road from Ellensburg to Cle Elum. The turn off to Liberty, Washington is
located 3.5 miles from the Virden junction on the left side of the road. The
Red Top turn off is located 7.5 miles from the Virden junction at U.S. Route
97 and Blue Creek Road (Forest Road 9738, the first left turn past Mineral
Springs Resort). Swauk Creek Camp Ground is located 11.5 miles from the
junction, and Blewett Pass (or Swauk Pass as some maps name it) is 14
miles from the junction.
The tour in this section of the guidebook shown in Figure 21 gives an
overview of the geology in this area and points out several established
recreation locations managed by the Wenatchee National Forest Service.
These locations provide opportunities for people to enjoy and interact with
the natural environment. This section of the guidebook also discusses the
human history related to the mining activities of over a century that fueled
much of the immigration of European Americans into this area and other
portions of the western United States. The gold mining activities of this area
centered on Swauk Creek that runs along side U.S. 97 primarily at the
Liberty town site and Blewett (Swauk) Pass areas.
At Red Top there is a restored Forest Service fire lookout post that is
often manned by volunteers who specialize in the study of Raptors. The are
also agate beds here, open for public digging. At the top of Blewett (Swauk)
Pass is the Swauk Forest Discovery Trail, a guided interpretive trail that
provides an overview of the trees and forest management practices of the
Wenatchee National Forest.
Liberty Area Tour
The lure of “Gold” fueled the development of the west and drew the
first white settlers to the Liberty area. Miners in the hundreds descended on
Liberty to work the placer deposits. Benton Goodman found the first piece
of Liberty gold in 1867. Since this time thousands of professional miners
and weekend amateurs have tried their hand at “panning for gold.”
Gold is a soft, but heavy metal, found in quartz veins, metamorphic
rocks or in small pieces eroded from them and deposited in river sediments.
It has been used for centuries for trade and was popular because of its many
uses. Being a soft metal allows it to be shaped easily, and its color made it
attractive for jewelry.
Gold is found in this region because of the geologic activities related
to its formation. It is associated with hydrothermal (water, heat) activity
55
related to the nearby igneous rock bodies. The major igneous formations in
this area are the Mt. Stuart Batholith and the Teanaway Basalt. The Mt.
Stuart Batholith and Teanaway Basalt Formations are discussed in more
detail in the Red Top section of this trip, as both formations can be seen
from this location.
Batholiths are large magma bodies that rise toward the earth’s surface.
They never actually reach the surface, but cool slowly inside the earth’s
crust. The hot magma essentially “cooks” the surrounding rocks as it rises
and comes in contact with them. This cooking changes the contact rocks,
metamorphosing them.
During this process water contained in the ground and within rocks
heats up and begins to flow. The hot water becomes rich with minerals, like
gold, and flows through and into the cracks in the surrounding rocks. Once
the fluids cool they become encased in the rock or become solid veins.
These rocks and veins are what miners look for. These types of processes are
usually associated with mountain building and this is why most mines are
located in mountain regions.
The gold found in this location is usually found in two forms, as
placer gold and as a wire form. Placer gold is a sedimentary form of gold
resulting from the weathering and erosion of the igneous or metamorphic
host rocks containing it. “Wire gold” is some of the purest found, up to 24
carats. This type of gold must be mined out of the host rock or the veins that
formed in the cracks or placer deposits.
The Liberty, Swauk, and Blewett areas are rich in mining history.
Numerous books and a video related to the mining history of this area are
available at both the Ellensburg and Central Washington University
Libraries, and several are listed at the end of this chapter. Mining continues
in the region today, but no big gold finds have occurred lately. Most of the
mining today is done as a weekend hobby and consists of panning and
sluicing. It is a fun and inexpensive hobby that allows a person to be outside
and near the water, but rarely yields little more than a few flecks.
Mining on a larger scale can be very destructive to the environment by
polluting the water with too much sediment or the chemicals associated with
removing gold from rock. Water pollution kills the plants and animals that
come in contact with it, so it is important to remember we share the water
with other living things and respect their needs as well. The best locations
for panning are along Williams Creek that runs along the road into the
Liberty town site and under the bridge where the Williams and Swauk
Creeks join at the Liberty Road turn-off.
56
The town site of Liberty consists of a few remaining homes, a post
office and general store. The area is littered with the relics of the mining
boom. Many of the buildings mark the location of some of the bigger mining
operations. The general store houses a few relics, but its hours of operation
are sporadic.
The Red Top Tour
Blue Creek Road (forest road 9738) is the road leading to Red Top. It
is the first left turn off of U.S. Route 97 after the Mineral Springs Resort.
From the turn, the Red Top parking area is located approximately 7 miles up
Blue Creek Road. This is a forest service fee area and a day pass must be
purchased to park in the lot. The best overview of the geology is from the
Red Top Lookout that sits on the Teanaway Basalt flow.
The hike to the lookout is about a quarter mile and has a steep grade.
If you take it slow it is possible for just about anyone to make the trip up. A
360-degree view is visible from this location. The north view is exposes the
landscape areas of Mt. Stuart Batholith, the Ingalls Tectonic Complex, the
Swauk and Roslyn-Chumstick Formations. To the south the view exposes
the Teanaway Basalt, Lookout Mountain, and Mt. Rainier. The view to the
west exposes the Roslyn-Chumstick Formations that make up Cle Elum
Ridge.The view to the east is on the public agate beds. These beds consist of
the weathered top portion and sediments from the Teanaway Basalt outcrop.
Figure 22. Overview of the Geology Surrounding Red Top Lookout
57
The illustration above in Figure 22 depicts the relationships between
the different formations making up the underlying geology of this area. The
variety of geologic features is in part of the county make it especially
interesting. Their interpretation is complex and has been the subject of over
of decade of formal academic studies that will continue to intrigue scientists
to come. The individual formations are discussed in relation to their ages,
beginning with the oldest and working forward through time to the youngest.
Ingalls Tectonic Complex – 150 Million Years Old
The Ingalls Tectonic Complex is a slice of metamorphosed crustal
rocks displaced by the Mt. Stuart Batholith. It is believed to have been made
of old ocean crust that was very deformed from being stuffed into the trench
along the coast of the ancient North American Continent. It was then forced
into its tilted position by the rising magma of the Mt. Stuart Batholith. The
heat and pressure created by the intrusion of the batholith “cooked” some of
these rocks, and transformed them from peridotite crustal rocks into a
metamorphic rock type called serpentine. Serpentine is often called
soapstone because it feels slippery like soap and got its name because of its
‘serpent skin” appearance. It is usually green in color and soft enough to
carve. A good exposure can be found on the West Side of the U.S. Route 97
at the top of Blewett (Swauk) Pass.
Mt. Stuart – 93 Million Years Old
The most prominent feature on the landscape to the north is the Mt.
Stuart Range. This formation is a batholith. As part of the plate tectonic
evolution of the state a number of plutons and batholiths were associated
with the accretion of the North Cascade Terranes (90 –100 million years
ago), and the Insular super-terrane in British Columbia.
Plutons and batholiths are masses of magma that crystallize (cool)
deep underground, and the names refer to their size. Batholiths are generally
regional in size and scale and plutons are smaller more localized rocks.
These hot magma bodies intruded into the existing rocks and may also fill
the cracks and faults within and surrounding them. The chemical make up of
the magma determines the kind of magma and resulting rock it is. How and
where the magma cools determines the texture of that rock type.
The Mt. Stuart Batholith is made up of a type of granite. Granite and
basalt are prominent features on the Washington landscape and are thought
to be the products of convergence between two plates. Why magmas are
different and exactly how they are created is not yet totally understood.
58
The sharp features seen on Mt. Stuart today are the result of the
glacial activities described in detail in the previous section of this
guidebook, The Thorp – Teanaway Glacial Features Guided Tour.
The Swauk Formation – 65-50 Million Years Old
The word Swauk is believed to mean “deep” and come from the
Indian word “Schwock.” The Swauk Formation is made up of thousands of
layers arkosic sandstone (80%), sandstone, conglomerates, and siltstone that
together form a unit 28, 000 feet thick. It has been recognized as one of the
most widespread sedimentary formations in the Cascades.
Found within this formation were thin coal beds containing fossil
palmetto fronds that could only have grown in a tropical or sub-tropical
environment. Samples of these fossils are located in the Kittitas County
Museum and in the Central Washington University Geology Department.
The Swauk Formation has been one of the most studied in the state
and its interpretation has changed over time. The dating of this formation
was an important piece of evidence in developing the structural history of
Washington State and the North American Plate.
The Swauk Formation is now located in a structural basin created by
faulting associated with the tectonic evolution of this region and remains one
of the States’ geologic mysteries. Several interpretations have classified its
sediments as continental shelf, coastal delta, or Lake deposits. Other
scientists have suggested that it is made up of a combination of all of these
deposits. There are several hypotheses, but no clear understanding has
developed.
The pieces of the Swauk Formation have been deformed by faulting
and intruded by thousands of Teanaway basalt dikes, as depicted in Figure 4.
As the scientific investigations of the different layers of the Swauk
Formation and their relationships to other rock units evolve, a clearer picture
of the formations’ development will emerge.
Teanaway Formation – 49 Million Years Old
The Teanaway Basalt was named for the river basin that is mostly
contained in. It is composed of basalt lava that was delivered to the earth’s
surface by what are called feeder dikes. The individual dikes are nearly
vertical and range in thickness from 15 to 150 feet thick and occurred in
swarms across this area up to Wenatchee, Washington.
The Teanaway Basalt flow occurs as a band up to 4 miles wide that
extends from Kachess Lake to Table Mountain. It ranges in thickness from
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about 1000 up to 5000 feet thick and is thought to have been deposited on
the slopes of older volcanoes. It is primarily a reddish-brown color and
contains numerous vesicles.
The vesicles found in the Teanaway Basalt became the hosts for
mineral rich fluids that percolated through the flow. These fluids entering
the flow were rich in silica and thought to be carried by cold water that
seeped through the basalt over a long period of time. Some of the individual
vesicles were filled with the fluid that then solidified into the banded blue
agates found within them. The blue color is the result of another unknown
mineral in the fluid solution and responsible for the name “Ellensburg
Blues.” Many other vesicle cavities were only partially filled and resulted in
hollow crystal filled cavities called geodes.
The agate beds located to the southeast of the Red Top Lookout have
been a popular “rockhounding” spot for nearly a century. The landscape is
littered with the remnants of digging and looks as though giant gophers
made this place their home. Many of the “Ellensburg Blues” were eroded
and washed out of the Teanaway Basalt flow due to the glaciation that began
in this region about 2 million years ago.
The Roslyn - Chumstick Formations – 43 Million Years Old
The Roslyn - Chumstick Formations were once thought to be part of
the Swauk Formation due to similarities in their structure and rock types. It
was classified as a separate rock unit, as depicted in the Figures 4 and 22,
when scientific investigations determined that the Teanaway Basalt
separated the Swauk and Roslyn formations. The Roslyn- Chumstick and
Wenatchee formations were deposited in a depression created by faults,
called a graben. Its age is believed to be 43 million years old. The Roslyn
Formation is the oldest of the three formations, then the Chumstick and last
the Wenatchee. All three formations are made up of sedimentary rocks and
appeared to be the same, until scientific investigations separated them based
on characteristics unique to each one.
The Roslyn Formation lies directly on top of the Teanaway Basalt and
thought to be 9,000 feet thick. It is described as a sedimentary unit
composed mostly of arkosic sandstone, sandstone, siltstone, claystones,
shales, interbedded with 30 coal seams. The origins of the sediments are
believed to have been an ancestral mountain range to the east.
The sediments were thought to have been delivered into a basin
consisting of a swampy environment of meandering streams and intermittent
lakes. The origin of the coal was the deposition of layer upon layer of
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organic materials (plants and animals) and numerous fossils of leaves, fish,
and a few turtles were found during the mining of the coal beds.
The first coal mining of this area began in 1882 and was expanded in
1886 by the Northern Pacific Railway. The coal seams were fairly horizontal
units that were entered from the base of the coal seam and mined by a
process called room-and-pillar. A room was carved into the coal seam that
was supported by beams that held up the roof. This process was repeated
over and over as the coal bed was followed into the ground. It was a
dangerous process and cave-ins were not uncommon. The Roslyn Museum
holds a good collection of pictures, artifacts, and history of the mining
activities from 1882 until 1965 in the Ronald, Roslyn, and Cle Elum,
Washington areas.
Fossil leaves can still be found in the red shale slag piles located
behind the Ronald, Washington Volunteer Fire Department off of State
Route 903. The piles are safe and open to the public, but the old mines and
sinkholes where the roofs have caved in are very dangerous.
The Chumstick is not well exposed in this area due to vegetation
covering the landscape, but is located toward the northeast of this viewpoint.
Its best exposure is between Leavenworth and Wenatchee, Washington and
make up the hills west of Wenatchee. It is another unit of sedimentary
deposits from a swampy environment, but coal beds found in it are thin and
suggest the area may have been drying out.
Literature on the Liberty and Blewett Areas
House, Neil, 1984. Liberty: A Mining History. Video. Darrel Corbert (Ed).
Jackson, Bob, 1978. The Rockhound’s Guide to Washington. Volume I, 47
p. University of Washington Special Collections on the Pacific
Northwest.
Josee, Jordan, 1967. You’re at Liberty Here: Mines and Miners of the
Swauk. Franklin Press Inc. Yakima, Washington. 103 p. Located in
the
CWU and Ellensburg Public Libraries.
Mayo, Roy F., 1975. Give me Liberty. Nugget Enterprises. Enumclaw,
Washington. University of Washington Special Collections on the
Pacific Northwest.
61
__________. 1985 “Gold,” Yours for the Digging. Nugget Enterprises.
Enumclaw, Washington. University of Washington Special
Collections on the Pacific Northwest.
__________. 1986. Liberty and Blewett: A Journey with Roy Mayo to the
Historical Mining Areas of Washington State. Nugget Enterprises,
Enumclaw, Washington University of Washington Special Collections
on the Pacific Northwest.
Moen, Wayne S. and Marshall T. Huntting, 1975. “Handbook for Gold
Prospectors in Washington.” Washington Department of Natural
Resources, Information Circular 57.
Tozer, Warren W., 1965. “The History of Gold Mining in the Swauk,
Peshastin, and Cle Elum Mining Districts of the Wenatchee Mountains,
1853 - 1899.” Masters Thesis, Central Washington University.
Literature on the Red Top and Swauk Areas
Bush, Thomas A. and Eric S. Cheney, 1996. “Guide to the Geology in the
Vicinity of Swauk and Snoqualmie Passes Central Cascade
Mountains, Washington.” Northwest Geological Society Guidebook
12.
Clayton, Daniel N., 1973. “Volcanic History of the Teanaway Basalt, EastCentral Cascade Mountains, Washington.” Masters Thesis. University
of Washington.
Evans, Edward E. and Samuel Y. Johnson, 1989. Paleogene Strike-slip
Basins of Central Washington: Swauk Formation and Chumstick
Formation. In Geologic Guidebook for Washington and Adjacent
Areas. Department of Natural Resources.
Foster, Robert J. 1960. “Tertiary Geology of a Portion of the Central
62
Cascade Mountains, Washington.” Bulletin of the Geological Society
of America. Vol. 71. pp. 99-126.
Goetsch, Sherree A., 1978. “The Metamorphic and Structural History of the
Quartz Mountain Lookout Mountain Area, Kittitas County, Central
Cascades, Washington.” Masters Thesis. University of Washington.
Majors, Harry M., 1974. The Swauk Formation 1841-1972: A Review of
Present Knowledge.
Miller, Robert B., 1975. “Structure and Petrology of the Ingalls Peridotite
and Associated Pre-Tertiary Rocks Southwest of Mount Stuart,
Washington.”
Masters Thesis. University of Washington.
Pongsapich, Wasant, 1970. “A Petrographic Reconnaissance of the Swauk,
Chuckanut and Roslyn Formations, Washington.” Master’s Thesis,
University of Washington.
Pratt, Ritchard M. 1958. “The Geology of the Mount Stuart Area in
Washington.” Ph. D Thesis. University of Washington.
Thompson, John P., 1961. Ellensburg Blue. Kittitas County Museum,
Altrusa
Club Project. Ellensburg Blue Bicentennial Commemorative Issue.
University of Washington Geology Department Staff, 1963. A Geologic Trip
Along Snoqualmie, Swauk, and Stevens Pass Highways. Division of
Mines and Geology, Information Circular No. 38.
Literature on the Roslyn-Cle Elum Area
Krueger, F., 1987. Roslyn Cemetery:Roslyn, Washington Historic
Cemeteries Tour, USA. Videocassette. 61 min.
Saunders, E.J., 1914. The Coal Fields of Kittitas County, Washington.
Washington Geological Survey Bulletin 9, 204 p.
Shideler, J. M. 1986. Coal Towns in the Cascades: A Centennial History of
63
Roslyn and Cle Elum, Washington. Spokane: Melior.
Upper Kittitas County Heritage Council, 1992. Roslyn Coal Mining.
Videocassette. 18 min.
Walker, C. S. 1980. “Geology and Energy Resources of the Roslyn-Cle
Elum
Area, Kittitas County, Washington.” State of Washington Department
of Natural Resources, Open File Report OF-80-1.
The Gingko, and Vantage
Guided Tour
The road leading to the Ginkgo Petrified Forest is no longer
designated with an official road number. It is informally know as the “Old
Vantage Highway” and is north of and runs parallel to I-90 (see Map 1, page
17). Take 8th street in Ellensburg east toward Vantage, Washington
approximately 26 miles to the trailhead of the Ginkgo Petrified Forest Trail,
or 28 miles to the Ginkgo State Park Interpretive Center. The Trees of Stone
Interpretive Trail is open year round and offers visitors 2.5 miles of trails in
which to view the different petrified trees found in the region.
The area between Ellensburg and Vantage, Washington drops in
elevation about 1000 feet. The areas’ precipitation level also drops, and the
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vegetation seen on the landscape is that of a shrub-steppe. A shrub- steppe is
an area covered mainly by short grasses and in this area is dominated by a
species of big sagebrush Artemisia tridentata. This area is known formally
as the Quilomene Wildlife Recreation Area and is bounded on the south by
the Boylston and Saddle Mountains and to the east by the Ginkgo State Park.
The Quilomene offers visitors a different kind of recreation
experience, as the desert conditions can be as beautiful, full of life forms,
and interesting features. This area blooms with wildflowers in the spring,
and is rich with birds, lizards, and snakes. It is a desert and preparations
should be made for adequate water and sun protection.
The trailhead for the Trees of Stone Trail is located on the left-hand
side of the road. The Interpretive Center located 2 miles ahead offers a free
trail guide, educational materials, and a film that describe the history of this
park.
The trail is numbered and the individual features are marked as to the type of
petrified wood that is being seen. The park was created to preserve a very
valuable part of the Natural History of Washington State. The features are
both natural and cultural resources for this region as they contribute to the
richness of experiences contained within it.
The founder of Ginkgo Petrified Forest State Park Professor George
Beck, discussed in detail in the Yakima Canyon Tour on page 40, is
responsible for the discovery of petrified wood in this region. His life’s work
was related to the geology and paleobotany of this area and his educational
contributions led to a greater understanding about many geologic and
archeological discoveries contained within Kittitas County.
A student of Professor Beck found the sample of petrified wood in
1931 that began the exploration of this area. It was the classification of the
sample as belonging to a subtropical tree called the Ginkgo that led
Professor Beck into his studies in this area. This discovery created a
scientific mystery because of its location in a desert. With his students he
explored a wider area and eventually more than 200 specimens were
collected that represented 30 different species of trees, not known to exist in
this region of the world. Oak, maple, hickory, elms, and walnut were some
of the logs found in addition to the Ginkgo. The remains found represented a
whole forest of trees, and led to questions of how they came to be located
here.
The environment of this area was very different in ancient times. It
was a region rich in vegetation and wildlife with large lakes and abundant
rainfall. This was the type of landscape these trees would have been found
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in. For a very long period of time the vegetation accumulated in a swampy
region and dead trees accumulated, were deposited and preserved in the
swampy lakebeds.
As plate tectonics began to redefine the landscape, by crumpling and
building mountains, changes in the climate and environment occurred.
Moisture from the Pacific Ocean was blocked by the new mountain ranges
and the eruption of volcanoes began to fill the region with volcanic debris.
The most significant volcanic events to the Park were the eruption of the
Columbia River Basalt Group. The particular lava flow these trees were
found in was named the Ginkgo Flow and is believed to be 15.5 million
years old.
These lava flows made it to this area and flowed into the lakes and
swamps containing the trees, and encased them in lava. Because these trees
were saturated with water they did not burn, but were preserved by
petrification. The process of petrification is not clearly understood, except it
is known that fluids rich in the mineral silica replaces the wood, then
solidifies into stone. The stone takes on the characteristics of the different
wood types and makes it possible to tell the genus and species of the tree it
once was. The minerals in the petrifying solution have sometimes altered the
color of the stone.
The Ginkgo Petrified Forest may have remained a mystery forever
had it not been for the glaciation of the northern portions of this region. The
events that uncovered this lava flow and the Petrified Forest, were giant
floods that carved out many of the landscape features seen today. The floods
were of such a magnitude that the landscape was scoured, uncovering this
treasure, leaving it to be discovered.
Petrified wood can be found throughout this area and to the south.
Several good collections can be seen at the Ginkgo Petrified Forest State
Park Interpretive Center, the Kittitas County Museum in Ellensburg, and in
the Central Washington University Geology Department.
Literature on the Ginkgo Petrified Forest
Barghoorn, Elso S. 1962. Wood of Ginkgo in the Tertiary of western North
America. American Journal of Botany 49:1095-1101.
Beck, George F., 1935. The quest of the sacred Ginkgo. Washington
Historical Quarterly 26:3-9.
__________. 1935. Fossil Bearing Basalts. Northwest Science 9:4-7.
66
___________. 1939. Life History of the Ginkgo Petrified Forest: An
Autobiography of an Ancient Oak Tree. CentralWashington College
of Education.
____________. 1944. Ancient maples of the Central Washington Region.
Northwest Science 18:4, 87-89.
__________. 1945. Ancient forest trees of the sagebrush area in central
Washington. Journal of Forestry 44 (3) pp. 334-338.
__________. 1945. Ancient Forest trees of the Sagebrush Area in Central
Washington. Journal of Forestry. 43: 5 p. 334-338.
Brockman, Frank C., 1950. The Story of the Petrified Forest. Tacoma: Print
Northwest.
Brown, Roland W. 1943. Some prehistoric trees of the United States.
Journal
of Forestry 41:861-868.
Washinton State Park and Recreation Commission, 1999. Trees of Stone:
The Story of the Ginkgo Petrified Forest State Park. Videocassette. 22
min. Seattle: Videoland Production.
Glossary of Terms
air-fall tuff –Rock made up of sediments of fine-grained pyroclastic particles
(volcanic ash and dust)
accreted - The addition of new land into older land by plate tectonics.
67
alluvium - A general term for sediment deposits made by streams on river
beds, flood plains, and alluvial fans; esp. a deposit of silt or clay laid down
during times of floods.
alluvial fan - An outspread, gently sloping mass of alluvium deposited by a
stream, esp. in an arid or semiarid region where a stream issues from a
narrow canyon onto a plain or valley floor.
alluvial stratum – Sediments deposited in layers.
anticline – An arched fold in which the rock layers usually dip away from
the axis of the fold.
arête - A sharp ridge that separates adjacent glacially carved valleys.
arkosic sandstone – A type of sandstone in which 25% of the grains are
made up of feldspar. The grains are usually angular and course suggesting
they were not transported a great distance and are believed to by derived
from a granite parent rock.
basalt - A fine-grained, mafic, igneous rock made of ferromagnesian
minerals and calcium-rich plagioclase feldspar.
basin – A bowl-like feature created in the landscape due to folding of the
underlying rocks.
batholith - A plutonic mass covering at least 40 square miles intruded into
the surrounding area.
bedrock – Solid rock that underlies soil or sediment.
buoyant – Tending to float above a denser liquid.
caldera – A large basin-shaped volcanic depression that formed when the
central section of a volcano collapsed.
carbon dating – A method used to date the decay of organic materials to
determine its age from decay rates.
cement – The solid material that precipitates in the poor space of sediments,
binding the grains together to form solid rock.
cirque – A steep-sided, amphitheater-like hollow carved into a mountain at
the head of a glacial valley.
coastal plain - A low broad plain that has its margin on an oceanic shore and
its strata either horizontal or very gently sloping toward the water.
Columbia River Basalt Group (CRBG) – The name given the plateau basalts
that cover the region of Washington, Oregon, and Idaho. The four main
groups of the lava flows that make up the CRBG are called the Imnaha,
Grande Ronde, Wanapum, and Saddle Mountain. The flows are 17.5 million
years old to 6 million years old. The Grande Ronde Basalt group makes up
85% of the total CRBG.
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columnar basalt structure – Volcanic rock in parallel, usually vertical
columns, mostly six-sided, also called columnar jointing. It can also occur as
platy jointing, described as looking like plates stacked one on top of another
in a column.
conglomerate - A sedimentary rock composed of rounded worn pebbles and
cobbles.
contact – The boundary surface between two different rock types or ages of
rocks.
continental shelf - That part of the ocean shore that lies between the
continental slope and the deep ocean floor.
contour line – A line on a topographic map connecting points of equal
elevation.
correlating stratigraphic sequences – The common connection of sediment
layers from different locations.
crystallization – Crystal development and growth. In sedimentary rocks,
crystal development is the result of precipitation of a solution. In igneous
rocks, crystals develop as magma or lava cool.
diatom - A microscopic single-celled plant with a shell of opaline silica.
diatomaceous earth - A mass of microscopic plant skeletons that form large
pure deposits of silica.
dike – A tabular intrusive structure.
dike swarms – A region where numerous sheet-like intrusive structures rise
from a batholith.
entrenched meander - An incised meander carves downward into the surface
of the valley in which it originally formed usually caused by rapid vertical
uplift of the surrounding land or a lowering of base level in the rivers outlet.
ecology - The science that studies the relationships between the different
elements and forms in a system, particularly the relationships between
organisms and the environment.
end moraine – A ridge of till piled up along the front of a glacier.
environment – The collection of surrounding things, conditions, or
influences; the air, water, minerals, organisms, and all other external factors
surrounding and affecting a given organism at any time; the social and
cultural forces that shape the life of a person or population.
feldspars – Group of the most common minerals of the earth’s crust. All
feldspars contain silicon, aluminum, and oxygen.
eolian –Sediments deposited by the wind.
fissures - An extensive crack, break, or fracture in the rocks, from which a
fissure eruption takes place.
69
fluvial – (a river) Sediments delivered by a river.
geode – A partially hollow, globe-like body found in cavernous rock.
glacier – A large, long-lasting mass of ice, formed on land by the
compaction and recrystallization of snow, which moves because of its own
weight.
glacial outwash – Material deposited by debris-laden melt water from a
glacier.
glacial striations – Straight scratches in rock caused by the abrasion by a
moving glacier.
graben – A down-dropped elongate block bounded by faults. A basin created
by faults.
Grande Ronde Basalt - the group of lava flows of the Columbia River Basalt
Group (CRBG) that make up 85% of all of the CRBG. This group erupted
from 16.5 million years ago until 15.6 million years ago.
granodiorite – A type of granite classified on the basis of its richness in
certain kinds of mineral components.
hanging valley – A smaller valley that ends abruptly high above a main
valley.
horn – A sharp peak attributed to cirques cut back into a mountain on several
sides.
hornblende – Common amphibole frequently found in igneous and
metamorphic rocks.
hummocky - A mounded or knoll like surface.
ice sheets – A glacier covering a large area (more than 50,000 square miles)
of land.
hydrothermal – Having to do with hot water or fluids.
hydrothermal metamorphism – The alteration of a rock by hot water passing
through it.
hydrothermal rock – A rock deposited by precipitation of ions from a
solution of hot water.
igneous - (from fire) A rock or mineral that solidified from molten or
partially molten material from a magma; also applied to processes related to
the formation of such rocks.
interglacial – A period of time in-between glacial periods.
landscape - The natural scenery within view.
lava - Magma on the earth’s surface.
lithification – The consolidation of sediment into sedimentary rock.
loess - A fine-grained deposit of wind-blown dust, usually associated with
glaciers.
70
micro-continent - A small continent made up of smaller continental
materials.
metamorphism - The mineralogical, chemical, or structural change occurring
to rocks due to pressure, temperature and/or heat.
metamorphic rock - Any rock that has been altered due to metamorphic
processes, not including weathering or erosion.
moraine – A body of till either being carried by a glacier or left behind after
a glacier has receded.
mudflow – A flowing mixture of debris and water, usually moving down a
channel.
natural history - The study of natural objects and organisms with reference
to their origins and their evolution within a native environment.
outcrop - The part of a geologic formation or structure that appears at the
surface of the earth.
outwash – Material deposited by debris-laden meltwater from a glacier.
palagonite – A type of rock created by lava flowing onto or into moist sand
or soil. Usually found at the base of a lava flow.
paleosols – Ancient soils.
peridotite – One of the most common member of a group of silicates. A
silicate is a substance that contains the mineral silica as part of its chemical
formula.
placer – A natural concentration of heavy metal and mineral particles, such
as gold or silver, in sand or gravel deposited by rivers or glaciers.
placer mine – Surface mines in which valuable minerals are extracted from
stream bar or beach deposits.
plate - A large, mobile slab of rock making up part of the earth’s surface.
plate tectonics – A theory that the earth’s surface is divided into a few large,
thick plates that are slowly moving and changing in size. Intense geologic
activity occurs at plate boundaries.
plateau basalt – Layers of basalt flows that have built up to a great thickness.
Pleistocene – An epoch of the Quaternary period characterized by several
glacial events. The Pleistocene is generally believed to have begun 2 million
years ago.
pluton – An igneous body that crystallizes underground.
pollen analysis – A method of obtaining information related to the types of
plants found in an area at a specific time. Different plants have unique
pollens that are deposited in sediments and can be used to interpret climatic
conditions of and area. Plants have specific ranges and a change in range
suggests a change in the conditions necessary for their existence.
71
pumice- A frothy volcanic glass.
quartz – One of the most common minerals of the earth’s crust having the
chemical symbol of SiO2.
radiometric dating - A method used to date the decay of organic materials to
determine its age from decay rates.
sandstone - A medium-grained sedimentary rock formed by the cementation
of sand grains.
sediments – Loose solid particles that can originate by (1) weathering and
erosion of pre-existing rocks, (2) chemical precipitation from solution,
usually in water, and (3) secretion by organisms.
sedimentary rock – Rock that has formed from (1) lithification of any type of
sediment, (2) precipitation from solution, or (3) consolidation of the remains
of plants or animals.
serpentine – A magnesium silicate mineral. Most asbestos is a variety of
serpentine.
siltstone - A sedimentary rock consisting mostly of silt grains.
stratigraphic sequences - Stratigraphy is the study of the layering of the
earth. Sequences are samples of the stratigraphy acquired in different
locations from field data and well drill data. Comparisons are made of the
sequences to determine if there are any relationships between them.
stratigraphy – The branch of geology dealing with the classification,
nomenclature, correlation, and interpretation of stratified rocks and
sediments.
structural basin - A structure in which the beds dip toward a central point.
syncline – A fold in which the layered rock usually dips toward an axis.
talus – An accumulation of broken rock at the base of a cliff.
tectonic forces – Forces generated from within the earth that result in uplift,
movement, or deformation of a part of the earth’s crust.
terminal moraine – An end moraine marking the farthest advance of a
glacier.
till – Unsorted and unlayered rock debris carried by a glacier.
topographic map – A map on which elevations are shown by means of
contour lines.
topography - The general configuration of a land surface, including its relief
and the position of its natural and man-made features.
Quaternary Period – The youngest geologic period that began approximately
2 million years ago and includes the present time.
tuff – A rock formed from fine-grained pyroclastic particles (volcanic ash
and dust).
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vesicle – A cavity in volcanic rock caused by gas in a lava.
vesicular – Volcanic rock containing cavities created by gas bubbles in lava.
weathering rinds - A concentric band of oxidized minerals found in basalt
rocks moved by glaciers
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