The Grand Coulee Ice Age Floods tour loop begins in Soap Lake and continues north to Lake Lenore Caves, Dry Falls Interpretive Center, Sims Corner, Electric City, Banks Lake, Northrup Canyon, Coulee City, Summer Falls, and Ephrata.
An overview of the catastrophic Ice Age Floods story and Soap Lake’s unique waters will be given. From Soap Lake two stops in the lower Grand Coulee will include Lenore Caves and Dry Falls At Lenore Caves the unique nature of the Columbia Basalt lava flows and its erosion will be discussed. Ample time will be allowed at Dry Falls (WA State Parks) to walk through the interpretive center. Next a brief stop to overview Dry Falls and the mouth of upper Grand Coulee will be done before driving up onto the Waterville Plateau to observe glacial features/deposits left by the Okanogan Lobe of the Cordilleran Ice Sheet. Eskers, kames, moraines, kettles and erratics will be some of the glacial landforms observed. Crown Point just north of Grand Coulee Dam will be the last stop before lunch. The interaction between Ice Age flooding and the Okanogan Ice Lobe will be discussed.
In the afternoon the tour will have a stop near Northrup Canyon and travel south through Coulee City to Summer Falls. The last stop will be at “Monster Rock” on the Ephrata “Expansion” Fan. This area was visited by the Jet Propulsion Laboratory (JPL) in the 1990’s prior to sending rovers to study Martian landscapes.