Banks Lake

Filling the floor of the upper Grand Coulee, eastern Washington state, USA. Looking more or less north. Banks Lake is doubly artificial; it's held in the Grand Coulee by dams at either end, and filled by Columbia River water pumped up using hydropower from Grand Coulee Dam! So it's filled by an artificial river as well. It's the master holding pond for the Columbia Basin irrigation project, as all the irrigated lands lie downhill from here. It can also be used as a "peaking pond"--the pumps can be run in reverse as generators for when the electrical load peaks. In effect electricity can be stored by pumping water up into the lake.
This pic gives a better scale of the lake--and remember, every drop was pumped up from the Columbia! The prominent mesa just visible at upper right is Steamboat Rock, a state park near the north end of the lake. We hiked to the top of it, with lots of pix elsewhere in this collection.