Lake Michigan–Huron (also
Huron–Michigan) is the combined waters of
Lake Michigan and
Lake Huron, which are joined through the wide, 20-
fathom (120 ft; 37 m) deep, open-water
Straits of Mackinac. Huron and Michigan are technically a single
lake because the flow of water through the straits keeps their water levels in near-equilibrium. (Although the flow is generally eastward, the water moves in either direction depending on local conditions.) Combined, Lake Michigan–Huron is the largest
fresh water lake by area in the world. If Lake Huron and Lake Michigan are considered two separate lakes,
Lake Superior is larger than either.