Yellow Belly Lake is a large alpine glacial lake in central Idaho’s Sawtooth Valley, within the Sawtooth National Recreation Area. In Custer County, it lies south of Stanley and northwest of Ketchum in the southern part of a mountain valley known for high-country lakes and broad views. The lake occupies a basin shaped by ice and is surrounded by forested mountain country, reflecting the region’s glacial landscape. Its size gives it a strong presence in this part of the valley. Reached from State Highway 75 by Sawtooth National Forest roads 205 and 096, it also serves as a practical destination for camping and day trips.