Yellowstone Lake is the largest body of water in Yellowstone National Park. The lake is 7732ft above sea level and covers 136sqmi with 110mi of shoreline. While the average depth of the lake is 139ft, its greatest depth is at least 390ft. Yellowstone Lake is the largest freshwater lake above 7000ft in North America.
In winter, ice nearly 3ft thick covers much of the lake except where shallow water covers hot springs. The lake freezes over by early December and can remain frozen until late May or early June.