Washougal is a city in Clark County, Washington, United States. The population was 14,095 as of the 2010 Census. Washougal was officially incorporated on December 4, 1908. Its Mount Pleasant Grange Hall is the oldest continually used grange hall in Washington. This small community is located on the Washington side of the Columbia River, with its lowlands and famous prairie situated on the west entrance to the scenic Columbia River Gorge. Wiki