The Volcanoes of Lewis and ClarkApril 30, 1806 |
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-- The Volcanoes of Lewis and Clark Map of the Journey -- Volcanoes, Basalt Plateaus, Major Rivers, etc. CALENDAR of the Journey -- October 1805 to June 1806 Along the Journey -- Pacific Northwest Maps - Columbia River, Volcanoes, Flood Basalts, Missoula Floods, Geology, etc. The Corps of Discovery -- The Journey of Lewis and Clark About the Reference Materials -- The Journals, Biddle/Allen, DeVoto, Gass, Moulton, Topo Maps, and others USGS Lewis and Clark Links -- Links to USGS Websites highlighting the Lewis and Clark Journey Resources Publications Referenced and Websites Visited |
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April 23-29 Up the Columbia, Rock Creek to Walla Walla |
April 30
The Walla Walla Shortcut, Overland, Walla Walla to the Touchet Walla Walla Vicinity, Walla Walla River, Palouse Loess (Sand) and the Palouse Hills, Eureka Flats, Touchet River |
CONTINUE
May 1-3 The Walla Walla Shortcut, Overland, Touchet to the Snake River |
| On October 7, 1805, Lewis and Clark and the "Corps of Discovery" began their journey down the Clearwater River and into the volcanics of the Pacific Northwest. The Corps travelled from the Clearwater to the Snake and down the "Great Columbia", finally reaching the Pacific Ocean on November 15, 1805. Along the journey they encountered the lava flows of the Columbia Plateau, river channels carved by the great "Missoula Floods", and the awesome beauty of five Cascade Range volcanoes. |
| The Volcanoes of Lewis and Clark |
| Heading Home - April 1806 |
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Walla Walla Shortcut Overland, Walla River to the Touchet River |
| Lewis and Clark are at the junction of the Walla Walla River with the Columbia River, beginning to prepare for an overland journey to the Snake River. Their camp of April 29, 1806, was on the north side of the Walla Walla. Today this spot is under Lake Wallula behind McNary Dam. View this area from the Fort Nez Perce/Fort Walla Walla historical signs near present Wallula, Washington, on U.S. Highway-12. |
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Walla Walla River:
Walla Walla River: The Walla Walla River flows out of the Blue Mountains, originating at nearly 6,000 feet and flows through narrow, well-defined canyons. After it leaves the mountains it flows through broad valleys that drain low, rolling lands. The principle tributaries of the Walla Walla River include the Touchet River, Mill Creek, and the North and South Forks of the Walla Walla River. The Walla Walla River basin drains an area of 1,758 square miles. According to Coues (History of the Expedition of Lewis and Clark, page 969), walla means running water, and redupliction of a word diminutizes it, so Wallawalla is the small rapid river. Lewis and Clark use the name Wallow Wallow, with several variations. Old Fort Walla Walla (For Nez Perce), at the mouth of the Walla Walla River, in Washington, was established in 1818 by the North West Company, and was abandoned in 1855. The city of Walla Walla, 33 miles east, came into importance in 1860-61, amid placer gold mining activities. It was first settled in 1855. -- Columbia Basin Fish and Wildlife Authority Website, 2002, and McArthur, 1982, Oregon Geographic Names Geology of the Walla Walla River Basin: As the river winds its way through the Walla Walla watershed, it crosses two major physiologic provinces: the Blue Mountains and the valley lowland. The Blue Mountains dominate the topography of the basin with an average elevation of 5,000 feet along the subbasin boundary, the highest point being Table Mountain at 6,000 feet. The topography of the Blue Mountains province consists of flat-topped ridges and steep stair-stepped valley walls formed by thousands of feet of Miocene basalt flows that engulfed the folded, faulted, and uplifted granitic core of the mountains. As mountains were uplifted, streams and glaciers carved canyons through the basalt layers. The valley lowland extends from the center of the basin north to the divide between the Touchet and Snake Rivers and south to the Horse Heaven Hills. Land surface elevations of the lowland province range from 2,500 feet at the base of the Blue Mountains to less than 270 feet at the confluence with the Columbia River. The dominant bedrock across the region consists of a series of basalt flows known as the Columbia River basalt that are stacked like a layer cake across much of eastern Washington, eastern Oregon, and southern Idaho. Dating from 10 to 17 million years before present, the basalt is divided into formations, each an aggregation of individual flows sharing similar flow histories and geochemistry. The three major formations that occur in the Walla Walla subbasin are the Saddle Mountains, Wanapum, and Grande Ronde. The flow thickness can range from five feet to as much as 150 feet, and collectively is estimated to be hundreds to thousands of feet thick. The topography of the basin is directly related to the folding, faulting, and erosion of these formations, creating a regional structure that dips westward from the Blue Mountains, southward down the Touchet Slope (the area between the Walla Walla and Touchet Rivers), northward from Horse Heaven Ridge, and eastward from a dividing ridge in the lower Walla Walla valley. During the Pleistocene ice ages, the region underwent severe change as the continental glaciers advanced and retreated to the north, and valley glaciers carved channels in the higher elevations. Massive floods swept through the Columbia basin periodically through the Quaternary era, bringing vast amounts of sediment into the region. -- Columbia Basin Fish and Wildlife Authority Website, 2002 |
| Although we had hobbled and secured our new purchases, we found some difficulty in collecting all our horses. ...... We have now twenty-three horses, may of whom are young and excellent animals, but the greater part of them are afflicted with sore backs. ...... At eleven o'clock we left these honest, worthy people accompanied by our guide and the Chopunnish family, and directed our course north 30o east, across an open level sandy plain, unbroken except by large banks of pure sand, which have drifted in many parts of the plain to the height of fifteen or twenty feet. |
| "... about 11 A.M we got our horses up by the assistance of the Indians and Set out. proceeded on over Smooth barron Sandy plains not a tree nor Shrub to be seen except a weed or Shrub like wild hysop which is common. the natives use it when dry for fires to cook with &C.; the Indian name of it is cum-cum ..." [Ordway, April 30, 1806] |
| "... This was a cloudy morning, and we stayed here till about 11 o'clock to collect our horses, and got two more; and have now altogether twenty-three horses. We then set out from Wal-la-wal-la river and nation; proceeded on about fourteen miles through an extensive plain, when we struck a branch of the Wal-la-wal-la river, and halted for the night. We saw no animals or birds of any kind, except two pheasants, one of which Capt. Clarke killed. The whole of this plain is of a sandy surface and affords but thin grass, with some branches of shrubs which resemble sage or hyssop. On the south side of this branch the soil is of earth and rich, covered with grass, and very handsome ..." [Gass, April 30, 1806] |
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Palouse Loess (Sand):
Fertile soils formed from Pleistocene silt and sand blanket the Walla Walla basin. During the Pleistocene ice ages, the region underwent severe change as the continental glaciers advanced and retreated to the north, and valley glaciers carved channels in the higher elevations. Massive floods swept through the Columbia basin periodically through the Quaternary era, bringing vast amounts of sediment into the region. Wind, intensified by the expanse of glacial ice, piled the sand and silt known as loess into dunes that spread across much of central and southeastern Washington. These dunes characterize the region known as the Palouse, and can be seen throughout the Walla Walla basin. -- Columbia Basin Fish and Wildlife Authority Website, 2002 
Palouse Hills:
Palouse Hills: The most characteristic feature of the Palouse is its rolling hills. Early geologists in the area first thought the Palouse deposits were formed by the weathering of basalt. Later studies showed that, based on the particle size and composition of the silt, or loess, the deposits were primarily transported here rather than formed in place. The best evidence shows that the Palouse loess was blown here as fine silt particles that collected in the dune-like shapes we see today. Loess is not particularly unique since nearly 10 percent of the earth's land surface is made up of accumulations of this wind-blown dust. Besides the Palouse, parts of the Mississippi Valley as well as large parts of Asia and central Europe are made up of loess deposits. These are regions of rich farmlands. In fact, most of the world's best agricultural soils are in loess. Loess is mostly associated with cool climates and usually forms in arid areas near glacial regions. Interestingly, no pre-Pleistocene loess has been recognized in the geologic record, although numerous pre-Pleistocene glaciations have been documented. The source area of the Palouse loess has been debated. Both volcanic ash from the Cascades and glacial flour from the ice margins of glaciated regions to the north have been deposited. Most likely, the Palouse loess was blown in from the fine-grained Ringold Formation on the eastern margins of the Cascades and perhaps from the Touchet Beds in the Pasco Basin. The composition of loess throughout the world is predominantly quartz and feldspar. The Palouse is no exception, but it also contains mica and small amounts of volcanic glass and dark minerals. Studies of the Palouse loess have shown that while the deposits of silt may look homogenous, or all of the same source and age, they are really composed of a complex series of layers formed in different episodes. Recent profiles have shown that the stratigraphy, or order of deposition, of these hills has been altered many times. These hills have not been stable, but are in a constant state of fluctuation. They were formed not once, but many times. The Palouse hills show a distinct alignment and dune-like form. This is due not only to the original dunes, but also to a number of factors that tend to steepen north-facing slopes and flatten the south-facing ones. From the air, or a vantage point on a "steptoe," the dune form of the rolling hills is dramatic -- gentle south-facing slopes and steep north-facing slopes aligned parallel to the prevailing southwesterly winds. More than one observer has likened the view to a sea of waves. -- Idaho Geological Survey Website, 2003 Geology of the Palouse: The Palouse, geologically, lies on the eastern edge of the Columbia Plateau. Between the surface of this plateau and much older "basement" rocks deep below is a great layer of 6- to 17-milion-year-old basalt. This basalt is what remains of a series of tremendous lava flows that once poured across the land. Fed by large cracks or fissures in the earth's crust, this lava ranged in thickness from a few feet to several hundred feet. In some places it traveled at speeds up to 30 miles per hour. And spread across 100 miles of terrain. The pre-basalt landscape -- whatever was here before the lava flows -- was completely engulfed in molten rock. Only a few small steptoes, the tops of the highest mountains, were spared. The Pliocene Epoch, about 2 to 5 million years ago, was a time of uplift and erosion in western North America. The Rocky Mountains were being pushed higher and the rising of the Cascades had begun. The Columbia Plateau, meanwhile, was being warped downward beneath the weight of the dense basalt. In this basin, stream and lake sediments were being deposited, particularly on the west side of the plateau near the Cascades in what today is known as the Ringold Formation. This period of deformation marked the end of the Tertiary Era and the onset of the Pleistocene Epoch, the time of the most recent Ice Age. During the late Pleistocene, near the end of the most recent Ice Age, glaciers had advanced from Canada into northern Washington sate and, in Idaho, down through the Purcell Trench to near where Coeur d'Alene is today. Glacial lakes were impounded at the margins of these huge lobes of ice. The largest known glacial lake in North America at that time was Lake Missoula. More than 13,000 years ago it emptied catastrophically because of a failure in an ice dam located near what is now Clark Fork, Idaho. A huge wall of floodwater cascaded down through the Spokane and Columbia River valleys in a torrent that probably lasted about a week. The famous channeled scablands of central Washington were carved by the terrible erosive force of this flood. The loess ground cover and some of the basalt layer beneath were washed away. The largest continuous scabland scoured by water is named the Cheney-Palouse tract and is over 80 miles long. Boulders, sand, and silt carried by the Missoula floodwaters were deposited in large bars on the Columbia River, and huge ripple marks along the drainages are visible from the air. As farmland, the most productive soil on the Palouse is that deposited most recently, in the Holocene Epoch. This soil, however, is also the most susceptible to erosion. Soil studies show that much of the Holocene topsoil has been lost through erosion, a constant problem in the fine-grained deposits. -- Idaho Geological Survey Website, 2003 |
| The rest of the plain is poor in point of soil, but throughout is generally short grass interspersed with aromatic shrubs [this area is referred to as the Eureka Flats] ...... |
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Eureka Flats:
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| At the distance of fourteen miles we reached a branch of Wollawollah river [Touchet River], rising in the same range of mountains [Blue Mountains], and empties itself six miles above the mouth of the latter [Walla Walla River]. It is a bold deep stream, about ten yards wide, and seems to be navigable for canoes. The hills of this creek are generally abrupt and rocky, but the narrow bottom is very fertile, and both possess twenty times as much timber as the Columbia itself; indeed, we now find, for the first time since leaving Rockfort [Rock Fort Campsite, The Dalles, Oregon], an abundance of firewood. ...... |
| "... we Continued our rout N.30o E. 14 ms. through an open leavel Sandy Plain to a bold Creek 10 yards wide. this stream is a branch of the Wallahwallah river, and takes it's rise in the same range of mountains to the East of the main branch. deep and has a bold Current. there are maney large banks of pure Sand which appear to have been drifted up by the wind to the hight of 20 or 30 feet, lying in maney parts of the plains through which we passed to day. This plain as usial is covered with arromatic Shrubs, hurbatious plants and tufts of Short grass. ... We encamped at the place we intersepted the Creek where we had the pleasure once more to find a Sufficency of wood for the purpose of makeing ourselves comfortable fires, which has not been the Case Since we left Rock fort Camp below the falls. ..." [Clark, April 30, 1806] |
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Touchet River:
Touchet River: The Walla Walla River flows out of the Blue Mountains, originating at nearly 1,800 meters (6,000 feet) and flows through narrow, well-defined canyons. After it leaves the mountains it flows through broad valleys that drain low, rolling lands. The principle tributaries of the Walla Walla River include the Touchet River, Mill Creek, and the North and South Forks of the Walla Walla River. The Touchet (at Bolles) drains approximately 935 square kilometers (361 square miles). -- Columbia Basin Fish and Wildlife Authority Website, 2003 |
| "... the narrow bottoms of this Creek is fertile. tho' the plains are pore & Sandy. the hills of the Creek are generaly abrupt and rocky. there is Some timber on this Creek. ..." [Clark, April 30, 1806] |
| "... we came about 16 miles and Camped on the wals-wal river [in error, they camped on the Touchet River] , which has narrow bottoms partly covred with Small timber ..." [Ordway, April 30, 1806] |
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The Camp - April 30, 1806:
On the Touchet River, 12 miles north of today's Touchet, Washington. |
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