Stevenson Island is a small, uninhabited island in Yellowstone Lake, Teton County, Wyoming. It was originally called Stevenson's Island after Colonel James D. Stevenson, and is now sometimes called Stevensons Island. The island is long and narrow, lying in a generally north-south orientation. At the widest, it is about 250 metres (820 ft), and the length is about 1,800 metres (1.1 mi) long. It is about 2.5 kilometres (1.6 mi) from the west shore of Yellowstone Lake, where Weasel Creek enters the lake.