“Our C o r h Shared d c i l a l n l l t e Geoheritage” e e e i e e r a h b n I c e S b c r “Geoheritage is the collection of natural wonders, landforms, o r T e F m and resources that have formed over eons and come to this L u b l u a generation to manage, use, and conserve effectively. Geoheritage n o l r P t a L h locations are valued for many reasons including: scientific, o e L e g a economic, ecological, education, cultural, aesthetic, artistic, and C v o d o b recreational purposes.” – American Geosciences Institute e i e n b R The recently designated Ice Age Floods National Geologic Trail, a o k which traverses parts of Montana, Idaho, Washington, and Oregon, L O G is a prime example of our shared geoheritage. Sites along the Ice Age Grand Coulee Dam l Floods trail highlight multiple geoheritage values and offer an Visitor Center Fort Spokane a Bridgeport c excellent opportunity to connect the public to the natural environment. Visitor Center i State Park a l

Steamboat Rock ! State Park Spokane L Ice Age Floods ! Coeur d’Alene a !Seattle Lincoln Rock k State Park Sun Lakes– d Turnbull National e National e Dry Falls e Wildlife Refuge b ! State Park M Wenatchee l Geologic Trail o i a e p L s In 2009, Congress established the Ice Age Floods National Geologic Trail, p n s s r the first ever national geologic trail. Still in the development stage, the o t n d o x IDAHO i a u National Park Service is coordinating the planning and development of the m e n Potholes h l a g trail with public and private landowners, local and tribal governments, the t State Park a a e ! C u l Map Symbols ! Ice Age Floods Institute, and other interested parties. The trail will consist Olympia !Ellensburg i P c b Missoula of an existing network of highways, roads, and footpaths which will offer e Ice Age Floods National - a a Geologic Trail, primary route interpretive opportunities to bring the story of the ice-age floods to visitors. g Ginkgo c e Petrified Forest S Ice Age Floods National c State Park \ Palouse Falls o Yakima a Wanapum Recreational Area State Park Geologic Trail, secondary route s Sportsman t l Yakima State Park in WASHINGTON ! Area affected by ice-age floods e Lewiston Geologic Features ! Lewis and Clark Select ice-age floods site The catastrophic force of the flood waters (see“The Interpretive Center The REACH with associated geoheritage values Floods” at right) left behind or exposed many different Hanford Reach geologic geologic features which can be seen along the trail. Some Interpretive Center Tri Cities recreation ! ! features of these features include: ecology MONTANA Astoria science economy • Bedrock features: colonnades, arches, entablatures ! Walla Walla & research culture • Erosional landforms: scablands, coulees, cataracts e r R i v • Depositional landforms: gravel bars, rhythmites, ripple marks a b i • Glacial features: erratics, moraines, kames, eskers, drumlins Columbia Hills u m Historical Maryhill o l • Wind deposits: dunes, loess hills Beacon Rock State Park State Park C Pendleton • Fossils: petrified wood, mammoth bones n State Park !

! a Geologic features can be seen at sites all along the Ice Age Floods Portland National Geologic Trail, including: Palouse Falls State Park The Floods e During the last ice age, between 12 and 17,000 years ago, glaciers covered much of Steamboat Rock State Park Sun Lakes–Dry Falls State Park northern Washington, Idaho, and Montana. The ice was miles thick in places. Portions of the glaciers c repeatedly blocked large river drainages, forming ice dams. Lakes formed behind the ice dams, growing to small Beacon Rock State Park Ginkgo Petrified Forest State Park inland seas rivaling the size of the Great Lakes.

O The largest of these glacial lakes was Glacial Lake Missoula in what is now Montana. The lake was approximately 2,500 feet deep in places and extended over 3,000 square miles. It held as much water as about half of Lake Michigan. When the ice c dam burst, all of the water suddenly drained in a matter of days, surging over Idaho, eastern OREGON Washington, and Oregon. The vast amount of water moving over a very short period of time i carved the deeply scoured terrain that forms much of the dramatic landscape we see today. Palouse Falls 2 Dry Falls 3 Beacon Rock 4

f In the aftermath of the initial flood, the process of river blockage, ice-dam lake formation, and

i catastrophic release occurred repeatedly. Evidence suggests that there could have been as many as 100 separate floods at intervals of about every 50 years.

c The features it created are colossal. The water plucked giant columns out of the basalt, created smoothed mesas and

a giant potholes, and formed ripple marks between 15 and 30 feet tall. Collectively, this landscape is called the Channeled White Bluffs Touchet beds 5 Seep Lakes 6 Ginkgo Petrified Forest 7 Scablands. The floods left behind many other distinctive features, such as, buttes, coulees, and flood bars. Palouse River Canyon 1

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Culture Economy Basalt columns 8 Ripple marks 9 Cape Disappointment 10 The unique landscape left by the floods has been used by The economy of the channeled scablands and the Pacific Native Americans for centuries. Historic campsites, Northwest is supported by features created by the floods. petroglyphs, stone and bone tools, and other relics found along the The voluminous Columbia River discharges an average of 264,900 paths of the floods, help us to better understand these ancestral cubic feet per second. Industry in the dryland regions of eastern Science & Research peoples whose descendants still populate the region. Washington depends on this lifeline for transportation, energy, Historical research of the floods has contributed to our The terrain left by the floods also influences how present-day agriculture, earth materials, and irrigation. understanding of catastrophic processes. Ongoing research Washingtonians use this region. Cultural exhibits at many of the has helped us understand the sources of ice-age flood selected sites have more information on the lives and livelihoods of Places to go: Grand Coulee Dam Maryhill State Park waters, the effects vast amounts of water had on surface topography, those who call this territory their home. Recreation Ecology and the intervals at which these floods occurred. The ice-age floods left behind prime landscapes for recreation. State The shrub steppe ecology found in eastern Washington supports many Current research on these landscapes is now being conducted by Places to go: Columbia Hills Historical State Park Parks, wildlife refuges, and other protected land ensures continued types of species only found in this type of environment. Flood-scoured NASA. The channeled scablands closely resemble the surface of availability for public use and wildlife habitat. Visitors can take in the basalt formations provide unique habitat for wildlife. The Hanford Mars, and offer a much closer locality for hands-on study. By Lewis & Clark Interpretive Center Fort Spokane Visitor Center stunning views while hiking, camping, hunting, fishing, rock climbing, boating, Reach region on the Columbia River provides habitat for a number of different studying the catastrophic effects of the water on the basalt landscape bird watching, or wildlife viewing. species including migratory birds, native mammals, and spawning salmon. of Earth, scientists can correlate these to similar features on Mars.

Places to go: Potholes State Park Beacon Rock State Park Places to go: Turnbull National Wildlife Refuge Bridgeport State Park Places to go: The REACH-Hanford Reach Interpretive Center

Lincoln Rock State Park Sun Lakes–Dry Falls State Park Yakima Sportsman State Park Ginkgo Petrified Forest State Park

Palouse Falls State Park Vineyards in eastern Washington 23

Wheat harvest and Grand Coulee Dam 24 Native Americans fishing at Celilo wind turbine 22 Falls (now inundated by Lake Celilo) 21 Petroglyphs at Ginkgo Petrified Forest State Park 20

Data Sources: Ice Age Floods National Geologic Trail routes adapted from Ice Age Floods National Geologic Trail Long-Range Interpretive Plan Master Trail Map. Glacial ice and ice-age flood affected areas modified from Silkwood, J.T. (1998), Glacial Lake Missoula and the channeled scabland : a digital portrait of landforms of the last ice age, Washington, Oregon, northern Idaho, and western Montana, United States Forest Service, Northern Region, Minerals & Geology, Geology Program Digital Mapping. Boating and fishing on Hiking below Dry Falls 13 Wildflowers above Sockeye salmon 17 Geologists collecting rock samples Photo credits: 1, 2, 3, 10, 13, 15, 16) Daniel Coe, Washington Division of Geology and Earth Resources; 4, 23) Dave Norman, Washington Division of 11 15 19 Geology and Earth Resources; 5, 6, 7, 9) Washington Geologic Survey Photo Collection; 8, 20) J. Whitmer, Washington Geologic Survey Photo Collection; the Yakima River Palouse Falls above Lake Roosevelt 11) Washington Department of Fish and Wildlife, http://bit.ly/2e33bpY; 12) George Gentry, U.S. Fish and Wildlife Service; 14) Washington Department of Fish and Wildlife, http://bit.ly/2dLKlF5; 17) Dave Menke, United States Fish and Wildlife Service National Digital Library; 18) David Weiss, National 12 14 Aeronautics and Space Administration/University of Arizona; 19) Michael Polenz, Washington Division of Geology and Earth Resources; 21) Sean Linehan, Bird watching Bull elk White pelican at Basalt columns in the Channeled Scablands (left) National Oceanic and Atmospheric Administration Historic Fisheries Collection; 22) Joe Smillie, Washington State Department of Natural Resources; 24) Hanford Reach 16 compared with basalt columns on Mars (right) 18 United States Bureau of Reclamation, http://on.doi.gov/2dtiVli