Lake Roosevelt

Franklin D. Roosevelt Lake is the reservoir created in 1941 by the impoundment of the Columbia River by the Grand Coulee Dam in Washington state. It is named for Franklin D. Roosevelt, who was president during the construction of the dam. Covering 125 square miles, it stretches about 150 miles from the Canada–US border to Grand Coulee Dam, with over 600 miles of shoreline; by surface area it is the largest lake and reservoir in Washington. It is the home of the Lake Roosevelt National Recreation Area.

The reservoir lies in parts of five counties in northeastern Washington; roughly in descending order of lake acreage they are Ferry, Stevens, Lincoln, Okanogan, and Grant counties.

Source: Wikipedia