Yellowstone Lake, located at 7,732 feet (2,376 m) above sea level, covers 136 square miles with 110 miles (177 km) of shoreline. Its deepest spot is at least 390 feet. Yellowstone Lake is the largest freshwater lake above 7,000 feet in North America.The lake freezes by early December (except for hot spots on its southern shore) and can remain frozen until early June.
Lehardy Rapids is downstream from Yellowstone Lake. In early summer, we have seen at least a Yellowstone cutthroat trout a minute jumping over the rapids, heading to Yellowstone Lake tributaries to spawn. This time, we see only a few trout hanging out in backwater eddies. Lake trout, introduced into Yellowstone Lake at some point in the past, eat young cutthroats in the lake. The population growth of this non-native species has dramatically reduced cutthroat numbers between Yellowstone Falls and the lake over the last ten years.