Yellowstone Lake

Yellowstone Lake Yellowstone Lake freezes over completely in winter, with ice thicknesses varying from a few inches to more than two feet. The lake's basin has an estimated capacity of 12,095,264 acre-feet of water. Because its annual outflow is about 1,100,000 acre-feet, the lake's water is completely replaced only about every eight to ten years. Since 1952, the annual water level fluctuation has been less than six feet.