Tustumena Lake is a lake on the west side of the Kenai Peninsula in southcentral Alaska, within Kenai National Wildlife Refuge and near the town of Kasilof. The lake is 25 miles (40 km) long and up to 6 miles (9.7 km) wide and receives drainage from Tustumena Glacier, and several creeks. Tustumena Lake is Alaska's 8th largest lake. The outlet forms the headwaters of the Kasilof River. The lake and the area around it are known for game hunting, and for the Tustumena 200 Sled Dog Race. This lake has a reputation for being very dangerous to small boats due to the high winds that regularly blow off of Tustumena Glacier. Early Russian explorers wrongly believed that this lake and Skilak Lake were a single body of water.