Completed in 1933; the water storage capacity created by the 140-foot dam is 450,000 acre feet. Here, according to Indian legend, was the habitat of Wishpoosh, an enormous beaver who roamed over the earth destroying lesser creatures. At that time, only the animal people inhabited the earth. Speelyia, the Coyote-god, challenged Wishpoosh to combat, and during the struggle that followed, Wishpoosh tore out the banks of the Keechelus, sending most of the water rushing down the canyon, creating many lakes in the Yakima Valley. The greatest lake of all, backed up by the Umatilla Highlands and the Cascades, finally broke through the mountains and created the Columbia River. Wishpoosh was washed into the ocean, where he devoured whales and fish, until Speelyia, transforming himself into a floating branch, drifted down the river and into Wishpoosh’s mouth. Once inside, Speelyia resumed his former shape and size and with his knife-edged teeth slew the belligerent beaver. He then divided the carcass of Wishpoosh and from it formed Indian tribes. This eight-mile-long lake with a mile average width is northwest of Cle Elum in northwest Kittitas County. A dam at the southeast end was completed in 1933. It controls the water level for irrigation purposes. In prehistoric times a glacial moraine formed the lake by blocking the flow of a river.