Lake McSwain is a reservoir located in Mariposa County, California. The lake was constructed in 1967 as part of the Merced River Flood Control Project. Water is supplied from the nearby Merced River, snowpack from the Sierra Nevada Mountains, and rainfall. The lake is primarily used for hydroelectric power generation but also provides irrigation for nearby agricultural lands. Recreational activities include fishing, boating, and camping. The lake is stocked with rainbow trout, brown trout, and catfish. The lake and surrounding area are managed by the Merced Irrigation District. Despite being a man-made lake, it provides a vital habitat for a range of species, including bald eagles and black bears.