Lewis Lake is located in the U. S. state of Wyoming in the southern part of Yellowstone National Park, about 4 miles (6.4 km) southeast of Shoshone Lake, and approximately 10 miles (16 km) southwest of Yellowstone Lake. Lewis Lake and Shoshone Lake are both located a few miles northeast of the Pitchstone Plateau. Like the river, Lewis Lake is named for Meriweather Lewis, commander of the Lewis and Clark Expedition