Columbia Hills State Park (which includes the Horsethief Lake area and Dalles Mountain Ranch area) is a 3,338-acre camping park with 7,500 feet of freshwater shoreline on the Columbia River. Horsethief Butte dominates the skyline. It stands over the lake like an ancient castle. The lake itself is about 90 acres in size and is actually an impoundment of the Columbia River. The lake was flooded into existence by the reservoir created by The Dalles Dam.