Geological fun fact
A continental divide, in the generic sense (as opposed to "the" Continental Divide in the Rocky Mountains), is a ridge along which any rivers on one side flow one way and any rivers on the other side flow the other way. The reason is, simply, water cannot (over any sustained distance) flow uphlil, so the ridge that is like the local maxima of height will divide it up. Based on this you'll get watersheds. Of course within these watersheds there are smaller divides, until you get down to the level of creeks.
In America, obviously, you will see a split between that which drains into the Pacific (Rocky Mountains and various Mexican mountain ranges), that which drains into the Gulf of Mexico (the Mississippi River watershed, which is a wonder of nature, and other smaller ones), that which drains into the Atlantic (east of Appalachians), and that which drains into the Arctic (don't actually know of any specific mountain ranges, Canaidan shield? glaciers?)
There is one river, though, that cuts through the Appalachian continental divide, the Susquehanna in Pennsylvania. That's interesting, as it means the river is actually older than the mountains, which are themselves the oldest mountains on Earth.
Additionally, and this is of interest given the news in A&N about Salt Lake City, there are things called endorheic basins wherever a bunch of continental divides landlock some section of land. It can't flow into the sea, so whatever water is there just stays there. Naturally these basins are mostly dry hot hellscapes (look at the map), but they often boast our large inland seas, such as the Salt Lake and the Caspian. Note, however, the existence of several endorheic basins in Canada and Minnesota.