The Art Gallery of    John Knapp

This page updated: 05/24/2006

In the Summer of 2002, Whitman College of Walla Walla Purchased a two paintings set of Dry Falls Washington.  The Work was done by me as a study of  how the falls might have looked 12,000 years ago. With the help of Dr. Bob Carson, Dr. Paul Yancey and Dr. Susan Weiler all of Whitman College, this work was completed, purchased and presented to the college. It now hangs in the new College Science Center Atrium as a permanent part of their instructional collection . 

At the bottom of this page is a copy of the description which hangs with this picture set in Whitman College.

Dry Falls, Washington

Dry Falls,Washington is located a few miles southwest of Grand Coulee Dam.  Much of the terrain of Eastern Washington was carved by a series of floods which occurred at the end of the last ice age.  A large glacier, which formed during the ice age, blocked the route to water from the Rocky Mountains south and west to the Pacific Ocean.  As the ice age drew to a close approximately 12,000 years ago, the glacier receded, and vast amounts of water stored in Lake Missoula burst through and covered Eastern Washington with a fast-moving flood.  Pictured above is a pastel painting of the northeastern portion of that flood's course as it appears today.  Below is my impression of that same cliff only 30 minutes into one of  hundreds of floods over many thousands of years. 

One hour into one of these events, the water level would have risen more than 50 feet above the high water level in this painting.  The two mammoths walking on the cliff rim were doomed, soon to be washed away.  
John Knapp 

DRY FALLS – THEN AND NOW (article which hangs beside the two painting set)

 Dry Falls is located between Upper and Lower Grand Coulee in the northwestern part of Washington’s Columbia Plateau.  The falls, 396 feet high and more than 3 miles wide (note two mastodons in upper left), formed during jökulhlaups (cataclysmic glacial floods) due to repeated failures of ice damming Montana’s glacial Lake Missoula.

            Long before the glacial floods, there were flood basalts.  About 15 million years ago, fissures opened in southeastern Washington and adjacent states.  Some of the basaltic lavas flowed northwest to the Grand Coulee area, where they form the bedrock at Dry Falls.

            With almost 500 cubic miles of water, Glacial Lake Missoula was the size of one of the Great Lakes.  The lake was dammed by a lobe of the Cordilleran Ice Sheet which moved from British Columbia south along Idaho’s Lake Pend Orielle.  The ice was about 2000 feet thick where it dammed glacial Lake Missoula at Cabinet Gorge.  Each time the ice dam failed, the jökulhlaup discharge was as much as 18 cubic miles of water per hour.  Perhaps one third of this water went west along the Spokane and Columbia Rivers to another ice dam at the present site of Grand Coulee Dam.  This ice dam directed the floods south along the Grand Coulee, forming the Earth’s largest ever known waterfall at Dry Falls.

            Series of floods occurred during many of the 10 or so glaciations in the Quaternary Ice Age of the past 2 million years.  Near the end of  the last glaciation, at least 40 floods occurred between 16 and 12 thousand years ago.  Each flood lasted perhaps a month and rushed across eastern Washington, through the Columbia River Gorge, and out to a lower Pacific Ocean.  The floods carved Washington’s Channeled Scabland, which consists of scabs (erosion remnants) like Steamboat Rock, and dry channels and waterfalls (like the Grand Coulee and Dry Falls).

                                                                                                text by:  R.J. Carson

References:

Allen, J.E., Marjorie Burns, and S.C. Sargent, 1986, Cataclysms on the Columbia: Timber Press, 211 p.

Baker, V.R., and Dag Nummedal, 1978, The Channeled Scabland: National Aeronautics and Space Administrations, 186p.

Bretz, J H., 1928, The Grand Coulee: American Geographical Society Special Publication 15, 89p.