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Wallula Gap basalts, right bank.
Image taken September 25, 2005.
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Columbia River Basalt ...
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The Columbia River Basalt is massive fissure lava flows which covered quite a bit of Idaho, Washington State, and Oregon. Formally called the Columbia River Basalt Group (CRBG), the flows are divided into five formations - the Saddle Mountains, Wanapum, Grande Ronde, Imnaha, and Picture Gorge Basalts. The majority of the CRBG flows are Early Miocene, between 17 and 5.5 million years old, and were erupted from north-south fissures near the present-day Washington-Idaho border. The CRBG consists of approximately 300 thick sequences of flood basalt flows, each flow from 10 to over 100 feet in thickness, with an estimated eruptive volume of at least 700 cubic miles, making them the largest documented individual lava flows on Earth.
The flows reached maximum thickness of 16,000 feet in the Pasco Basin, and in the Columbia River Gorge, 21 flows poured through forming layers of rock up to 2,000 feet thick. Concurrent with the CRBG eruptions was the folding and faulting of the basalt in the western part of the Columbia Basin, creating the "Yakima Fold Belt" of anticlines and synclines.
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Columbia River Basalt Views ...
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Twin Sisters, Wallula Gap, Washington.
Image taken September 26, 2004.
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Washington banks of the Columbia River, as seen from Celilo Park, Oregon.
Image taken October 2, 2006.
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Fulton Ridge basalt flow between the Deschutes River and Celilo Park, Oregon.
Image taken May 24, 2005.
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Basalt Flow and Union Pacific train, between The Dalles and Celilo, Oregon.
Image taken June 4, 2005.
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Horsethief Butte and Horsethief Lake.
View from Columbia Hills State Park (Horsethief Lake State Park).
Image taken September 28, 2011.
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Cape Horn, Washington.
Cape Horn as seen from Dalton Point, Oregon.
Phoca Rock is near the base of the cliff.
Cape Horn is a formation of Grande Ronde basalt flows which erupted in the Lower Miocene. The Cape Horn basalts are capped by Troutdale gravels, which in turn are overlain by the lavas of the small Mount Zion olivine basalt shield volcano of the Boring Lava Field.
Image taken October 22, 2005.
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Crown Point and Vista House, Oregon.
Crown Point is a remnant of a massive Priest Rapids intracanyon lava flow. The Priest Rapids is a member of the Wanapum Basalt of the Columbia River Basalt Group (CRBG), and erupted in the middle Miocene.
View from Portland's Woman Forum Scenic View (formerly Chanticleer Point).
Image taken October 22, 2005.
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Multnomah Falls, Oregon, with Benson Bridge.
Multnomah Falls, located near Portland, Oregon, drops 620 feet over Grande Ronde Basalt of the Columbia River Basalt Group. The Missoula Floods enhanced the cliff face, eroding away loose and softer materials. At Multnomah Falls the visitor can view six flows in the cliff face, with pillow flows being visible in the upper sequence near the lip of the Upper Falls.
Image taken March 6, 2005.
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The Horse Heaven Hills is an anticline in the eastern region of the Yakima Fold Belt, which was formed by north-south compression of Columbia River Basalt Group (CRBG) lava flows. The Columbia Hills lie in the western part of the Yakima Fold Belt.
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Mouth of the Snake River looking towards the Columbia River, at the Horse Heaven Hills.
Fishing docks are at Sacajawea State Park.
Image taken September 25, 2005.
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Columbia Hills, Washington.
View between Celilo and the Deschutes River.
Image taken September 26, 2004.
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From the Journals of Lewis and Clark ...
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Clark, October 18, 1805 ...
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This morning Cool and fare wind from the S. E.
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Took our leave of the Chiefs and all those about us [from their camp, the location of today's Sacajawea State Park] and proceeded on down the great Columbia river passed a large Island at 8 miles about 3 miles in length, a Island on the Stard. Side the upper point of which is opposit the center of the last mentioned Island and reaches 3½ miles below the 1st. Island and opposit to this near the middle of the river nine Lodges are Situated on the upper point at a rapid which is between the lower point of the 1st Island and upper point of this; great numbers of Indians appeared to be on this Island, and emence quantites of fish Scaffold we landed a few minits to view a rapid which Commenced at the lower point, passd this rapid which was verry bad between 2 Small Islands two Still Smaller near the Lard. Side, at this rapid on the Stard. Side is 2 Lodges of Indians Drying fish, at 2½ miles lower and 14½ below the point passed an Island Close under the Stard. Side on which was 2 Lodges of Indians drying fish on Scaffolds as above
[Today this reach has been inundated by the waters of Lake Wallula, the reservoir behind the McNary Dam. The Burbank Slough - part of the McNary National Wildlife Refuge - dominates the eastern bank of the Columbia and two islands which remain offshore of Wallula are Crescent Island and Badger Island.]
at 16 miles from the point [junction of the Snake River with the Columbia, location of today's Sacajawea State Park] the river passes into the range of high Countrey at which place the rocks project into the river from the high clifts [Wallula Gap] which is on <both> the Lard. Side about 2/3 of the way across those of the Stard Side about the Same distance, the Countrey rises here about 200 feet above The water and is bordered wth black rugid rocks [Columbia River Basalt], at the Commencement of this high Countrey [Wallula Gap] on Lard Side a Small riverlet falls in [Walla Walla River] which appears to passed under the high County in its whole cose Saw a mountain bearing S. W. conocal form Covered with Snow [Mount Hood, Oregon]. passed 4 Islands, at the upper point of the <first> 3rd is a rapid, on this Island is two Lodges of Indians, drying fish, on the fourth Island Close under the Stard. Side is nine large Lodges of Indians Drying fish on Scaffolds as above [Yellepit area];
at this place we were called to land, as it was near night and no appearance of wood [Lewis and Clark are in the Port Kelley area, where today the islands offshore are under the waters of Lake Wallula.], we proceeded on about 2 miles lower to Some willows, at which place we observed a drift log formed a Camp on the Lard Side [Spring Gulch] under a high hill nearly opposit to five Lodges of Indians;
Soon after we landed, our old Chiefs informed us that the large camp above "was the Camp of the 1st Chief of all the tribes in this quarter [Chief Yellepit], and that he had called to us to land and Stay all night with him, that he had plenty of wood for us &" This would have been agreeable to us if it had have been understood perticelarly as we were compelled to Use drid willows for fuel for the purpose of cooking, we requested the old Chiefs to walk up on the Side we had landed and call to the Chief to come down and Stay with us all night which they did;
... we made 21 miles to day.
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