A continental divide is boundary or ridge that separates a continent’s river systems. River systems on opposite sides of the divide will feed into a distinct ocean basin or sea. Every continent on Earth, except Antarctica, has a continental divide, and sometimes more than one.
North America is distinct in that it has two continental divides, although for most people, only one might easily come to mind. The divide that is most likely to be thought is the one formed by the Rocky Mountains in western North America. It is certainly the largest and most formidable of the two, stretching from northwestern Canada, through the United States, and into Mexico along the crest of the Sierra Madre Occidental. This spine causes precipitation falling to the west of it to drain into the Pacific Ocean, while precipitation falling to the east drains either northeast to Hudson Bay, or southeast to the Gulf of Mexico.
The other North American continental divide, known as the Eastern Continental Divide, runs along the ridgeline of the Appalachian Mountains. Along the eastern side, water drains into the Atlantic Ocean, while on the western side, water drains into the Mississippi River and the Gulf of Mexico.
This photo was taken at Logan Pass in Glacier National Park in Montana, USA with a Canon EF17-40 mm f/4 USM lens zoomed to 31 mm on a Canon EOS 5D Mk III. The exposure was set to 1/250 sec at f/19 and ISO 800.