Moccasin Dam is a small dam on Moccasin Creek in Tuolumne County, California, in the town of Moccasin, west of Yosemite. It holds the Moccasin Reservoir. The dam, reservoir and associated hydroelectric power plant are part of the Hetch Hetchy Project, which provide water and power to the city of San Francisco. The dam is located near the juncti…Moccasin Dam is a small dam on Moccasin Creek in Tuolumne County, California, in the town of Moccasin, west of Yosemite. It holds the Moccasin Reservoir. The dam, reservoir and associated hydroelectric power plant are part of the Hetch Hetchy Project, which provide water and power to the city of San Francisco. The dam is located near the junction of Highway 120 and Highway 49.