An unsuspecting coulee in the southern Channeled Scabland, Devil’s Canyon cuts a straight, south-southeast trending, 600-foot deep gash through the Palouse wheat lands from Kahlotus at the lip of the Washtucna Coulee to the Snake River at Lower Monument Dam. The straightness of the gash is reflective of major structural joints in the basalt bedrock and similar straight gashes are located to the east including the current Palouse River Canyon. This is one of many flood way channels carved during the Missoula Floods.
One of the largest flood routes sent water southeast from Spokane into the ancestral Palouse River Valley. The volume of water far exceeded the capacity of the entire valley and water spilled out of the top of the valley at multiple locations. One of these over spill routes became the new route of the Palouse River. The old river valley flowed though what is now Washtucna Coulee. Another over topping location is just south of the Town of Kahlotus into Devil’s Canyon.
Published by Bruce Bjornstadt on Ice Age Floodscapes (7:46 min): Nov 13; 2015