Redfish Lake is an alpine lake in Custer County, Idaho, just south of Stanley. It is the largest lake within the Sawtooth National Recreation Area. The U.S. Forest Service has developed some facilities for hiking, camping, and water sports on Redfish Lake while largely maintaining the natural landscape of the Sawtooth Mountains. On the north shore sit…Redfish Lake is an alpine lake in Custer County, Idaho, just south of Stanley. It is the largest lake within the Sawtooth National Recreation Area. The U.S. Forest Service has developed some facilities for hiking, camping, and water sports on Redfish Lake while largely maintaining the natural landscape of the Sawtooth Mountains. On the north shore sits a seasonal hotel and marina, Redfish Lake Lodge, which offers a cross-lake ferry service for hikers and sightseers in the summer.