Burt Lake is a 17,120 acre (69 km²) lake in Cheboygan County in the U.S. state of Michigan. The western shore of the lake is on the boundary with Emmet County. The lake is named after William Austin Burt, who, together with John Mullett, made a federal survey of the area from 1840 to 1843.The lake is approximately 10 miles (16 km) long from north to south, about 5 miles (8 km) at its widest, and 73 feet (22 m) at its deepest.