In what order does water flow through the Great Lakes?

The Great Lakes system generally drains from west to east, with water flowing through the lakes in the following order:

• Lake Superior is the headwater of the system and discharges into Lake Huron via the St. Marys River.1
• Lake Michigan flows northward into Lake Huron through the Straits of Mackinac. Because they share the same altitude and are hydrologically connected, Lakes Michigan and Huron are often considered a single lake.1
• Lake Huron discharges into Lake Erie via the St. Clair River, Lake St. Clair, and the Detroit River.1
• Lake Erie flows into Lake Ontario primarily through the Niagara River, which includes Niagara Falls, though some water is also diverted via the Welland Canal.1
• Lake Ontario serves as the final lake in the chain, discharging into the St. Lawrence River, which eventually empties into the Atlantic Ocean.12