What is the Continental Divide?

Michael Anissimov
Michael Anissimov

A continental divide is an imaginary line down a continent that demarcates whether water in the area will flow towards a given body of water (usually an ocean) or another. The most famous continental divide is the north-south Continental Divide of the Americas, sometimes known as the Great Divide or just the Continental Divide. This divide is more than 6,000 miles (9,600 km) long, stretching from the western tip of Alaska all the way to Tierra del Fuego at the southernmost tip of South America. This continental divide mostly demarcates whether water flows into the Pacific or Atlantic Ocean. Some areas close to the divide, like the Great Basin, are endorheic basins, meaning that they retain water in salt lakes or salt pans, and it never flows to the ocean.

Glaciers flow away from continental divides.
Glaciers flow away from continental divides.

In the United States, the Continental Divide does not go clear down the middle of the country, but follows the peaks of the Rocky Mountains, which are somewhat offset to the west. Immediately east of the Rocky Mountains and throughout most of the central United States, water flows to the Gulf of Mexico. In eastern North America there are three more continental divides: the Northern Divide, Eastern Divide, and the St. Lawrence Seaway Divide. These divides indicate whether water flows to the eastern seaboard, Hudson Bay and the Arctic Ocean, or the Gulf of St. Lawrence. For much of its length, the Northern Divide is located roughly at the border between the United States and Canada.

At Triple Divide Peak in Glacier National Park, in Montana, two important continental divides converge -- the Great Divide and the Northern Divide. There is a triple junction between the two branches of the Great Divide and the one branch of the Northern Divide, which begins at this point and runs east. Depending on where precisely on the peak you are standing, a drop of water will eventually flow to either the Gulf of Mexico, the Pacific Ocean, or the Arctic Ocean. Scientists consider this the hydrological peak of North America.

Continental divides worldwide dictate numerous features of the continents around them. Glaciers slowly flow in directions away from continental divides, carving out huge valleys and fjords in their wake. River systems flow away from continental divides, and many lakes which occupy glacier-carved valleys point away from continental divides. Oftentimes, a continental divide can be clearly seen just by looking at a high-resolution satellite photo of an area.

Michael Anissimov
Michael Anissimov

Michael is a longtime wiseGEEK contributor who specializes in topics relating to paleontology, physics, biology, astronomy, chemistry, and futurism. In addition to being an avid blogger, Michael is particularly passionate about stem cell research, regenerative medicine, and life extension therapies. He has also worked for the Methuselah Foundation, the Singularity Institute for Artificial Intelligence, and the Lifeboat Foundation.

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Discussion Comments


@geekish - Maybe you were at Alpine Ridge Trail at Rocky Mountain National Park, it is a part of the continental divide trail and it is close to Denver! Good luck "tracking" the trail!


@geekish - As far as where you were, I can help a little! There is an actual trail called the continental divide trail. It doesn't follow along the entire continental divide of the Americas, but it does go through Colorado.


I first found out about the Continental Divide of the Americas when I visited a friend in Colorado. However, I had thought for the longest time it was just the Colorado continental divide, as the signs we passed while hiking outside of Denver simply said, "continental divide."

We hiked in the morning and saw the sunrise as we went towards the trail's summit. It was beautiful! I would love to go there again.

Does anyone know where I might have been? It's been about a decade since I was there and can really only remember those signs that said "continental divide."


There are cyclists who have cycled along the continental divide. When I was looking at their pictures, I realized that there are actually signboards where the imaginary divide is that say "Continental Divide." I didn't really think there would be!

I also learned that all of the rivers that are located west of the continental divide flow into the Pacific Ocean. Rivers located east flow into the Atlantic Ocean.

I think I would like to travel up to the divide sometime myself.

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