|the watershed of a continent, esp (often caps.) the principal watershed of North America, formed by the Rocky Mountains|
A region of high ground, from each side of which the river systems of a continent flow into different continental-scale drainage basins. ◇ In North America, the Continental Divide is a series of mountain ridges stretching from Alaska to Mexico, marking the separation of drainage basins that empty into the Pacific Ocean or Bering Sea from those that empty into the Arctic or Atlantic Oceans or the Gulf of Mexico.
An imaginary geographic line defined by the fact that water poured on one side of it would ultimately flow into the ocean on one side of a continent, while water poured on the other side of the line would flow into the ocean on the other side of the continent.
Note: In North America, the continental divide is located in the Rocky Mountains.