Banks Lake

Looking south along the Grand Coulee from the top of Steamboat Rock. Steamboat Rock State Park, Washington state, USA. Banks Lake is doubly artificial: it's formed by dams at either end of the upper Grand Coulee (above Dry Falls and above Grand Coulee Dam), and is filled by water pumped up from the Columbia River by Grand Coulee Dam! "Coulee", btw, is a localism for a flat-bottomed canyon with steep sides.