Yellowstone Lake is a significant freshwater resource located in Teton County, Wyoming, with an area of 87,046 acres. Situated at an elevation of 7,733 feet (2,357 m) above sea level, it is the largest high elevation lake in North America, and is renowned for its stunning natural beauty and diverse aquatic ecosystem. With a length of approximately 20 miles (32.2 km) and a width of 14 miles (22.5 km), Yellowstone Lake boasts a shoreline spanning 141 miles (227 km) and a surface area of 132 square miles (342 km2). The lake is frozen completely every winter, with ice thickness varying from a few inches to over two feet. It typically thaws in late May or early June. Despite its impressive size, the water in Yellowstone Lake remains cold year-round, with an average temperature of 41°F (5°C), making swimming unsafe due to the risk of hypothermia. Yellowstone Lake is home to a diverse range of fish species, including the largest population of wild cutthroat trout in North America. The presence of these Pacific Ocean fish in a lake that drains to the Atlantic puzzled experts for years. However, recent research suggests that the lake once drained to the Pacific Ocean via Outlet Canyon and the Snake River, allowing fish to swim across the Continental Divide at Two Ocean Pass. The introduction of the invasive species lake trout now poses a significant threat to the native cutthroat trout population. The lake's only outlet is the Yellowstone River, which flows northward from the lake at Fishing Bridge. The elevation of the lake's northern end remains relatively consistent until LeHardy Rapids, leading many to consider the rapids as the true northern boundary of the lake. In conclusion, Yellowstone Lake is a spectacular freshwater resource in Teton County, Wyoming, with an extensive area and diverse ecosystem. While it remains a popular destination for recreational activities such as fishing, boating, and wildlife viewing, visitors must exercise caution due to the extreme cold of the water. The lake's unique history and present-day challenges provide a fascinating glimpse into the complex interactions between geology, climate, and ecology in the region.