December 15, 2008
The Horsethief Lake area at the Columbia Hills State Park on the Columbia River in Washington State provides the opportunity to observe closely the effects of the flooding that occurred through much of Washington during the last ice age. In this photograph, taken September 13, 2008, a river wall that was scoured by the repeated flooding had its topsoil removed. This topsoil lay on top of the basalt that was created 15 million years ago. In the background are similar sloping hills that were not touched by the floods, giving an indication of what the Columbia Gorge may have looked like if the floods had not occurred. Much of the geographic evidence of the ice age floods was drowned when the Columbia River Dams were built. Horsethief Lake itself was created by The Dalles Dam which was built in the late 1950s. Apparently, the lake's name was coined by dam workers who had seen too many Western movies.