Big Bear Lake is a reservoir in the San Bernardino Mountains, in San Bernardino County, California, United States. At a surface elevation of 6,750 ft (2,060 m), it has an east-west length of approximately 7 miles (11.2 km) and is approximately 2.5 miles (4 km) at its widest measurement, though the lake's width mostly averages a little more than 1 mile (1.6 km). These approximations are based on the lake having an optimum retainable water level. At dam's end Big Bear measures its deepest water at 72 feet (22 m). It is a completely snow-fed lake, having no other means of tributary or mechanical replenishment.