These streams then flow into different river systems, which may empty into different oceans. The little streams are called the headwaters of the river systems. The divide separates the headwaters of the systems. A divide may be rather low, like the height of land that runs from east to west across North America. This divide separates the rivers that flow generally northward into the Gulf of Saint Lawrence, Hudson Bay, and the Arctic Ocean from those that flow into the Mississippi basin.
Some divides are very high with steep slopes, like the Rocky Mountains.
This separates the rivers flowing into the Mississippi and the Gulf of Mexico from those flowing into the Pacific Ocean. The divide that runs north and south through the Rocky Mountains is called the Great Divide or the Continental Divide. On Cutbank Pass in Glacier National Park, there are three brooks so close together that a person can pour water into all three at the same time. One brook carries water to Hudson Bay, another to the Pacific Ocean, and the third to the Gulf of Mexico. In the Rocky Mountains, sources of streams flowing to the Pacific and to the Gulf lie only a short distance apart.