Lake Michigan–Huron is the body of water combining Lake Michigan and Lake Huron, which are joined through the 5-mile-wide, 295-foot-deep, open-water Straits of Mackinac. Huron and Michigan are hydrologically a single lake because the flow of water through the straits keeps their water levels in overall equilibrium. Although the flow is generally eastward, t…Lake Michigan–Huron is the body of water combining Lake Michigan and Lake Huron, which are joined through the 5-mile-wide, 295-foot-deep, open-water Straits of Mackinac. Huron and Michigan are hydrologically a single lake because the flow of water through the straits keeps their water levels in overall equilibrium. Although the flow is generally eastward, the water moves in either direction depending on local conditions. Combined, Lake Michigan–Huron is the largest freshwater lake by area in the world. Lake Superior is larger than either individually, so it is counted as the largest of the Great Lakes when Lake Michigan and Lake Huron are considered separately.