The Saint Lawrence Divide is a continental divide in central and eastern North America that separates the Great Lakes-St. Lawrence River Basin from the areas to the south. Water, including rainfall, snowfall, lakes, rivers and streams, north of the St. Lawrence divide, drains into the Gulf of St. Lawrence; water south of the St. Lawrence divide will drain into the Atlantic Ocean east of the Eastern Continental Divide, or drains into the Gulf of Mexico if it falls on the land west of the Eastern Continental Divide. The divide is one of five continental water divides in North America that demarcate several watersheds that flow to different gulfs, seas or oceans.

The Hill of Three Waters is a triple divide on the Laurentian Divide located about two miles north of Hibbing, Minnesota. From this hill, the Eastern Continental Divide follows the lower Appalachian Mountain to form the height of Land separating the Atlantic watershed from the Mississippi River watershed.