Sawtooth Lake, Glacial lake in Sawtooth Mountains, Idaho, US.

Sawtooth Lake is a glacial lake in the Sawtooth Mountains with clear water held in a high mountain basin surrounded by steep rocky slopes. Iron Creek feeds the lake, and the shores are characterized by rocky terrain and alpine vegetation typical of high elevation areas.

Sawtooth Lake lies in Custer County, Idaho, in the Sawtooth Wilderness of the Sawtooth National Recreation Area, about 6.8 miles southwest of Stanley. It sits at 8,435 feet, with Mount Regan rising to 10,190 feet at its southern end. The Iron Creek trailhead, reached via State Highway 21 and forest road 619, is about 5 miles from the lake.

The Iron Creek Trail to Sawtooth Lake is one of the most popular hikes in the Sawtooth National Recreation Area, a 5-mile route gaining 1,710 feet that takes 5 to 6 hours round trip. Camping is allowed anywhere in the national forest, and the lake often serves as a base camp for further hikes through the northern Sawtooth Wilderness. Wilderness permits are obtained at trailheads.

This lake sits at high elevation and is accessible only during warmer months when snow has melted away. The hiking trail to reach it is challenging and requires good physical fitness and proper outdoor gear.

Sawtooth Lake sits at 8,435 feet and often stays frozen into early summer, so hikers crossing it in July may still walk on snow. The southern shore lies beneath Mount Regan, 10,190 feet high, and the basin also holds Regan Lake and Trailer Lakes.