Where does Hawk Creek, southwest of Willmar, end up? How about Cherry Creek, north of St. Peter? Or Goose Creek, near Albert Lea?
You can probably guess. They all end up part of the Mississippi River, which drains most of the United States.
You can click on any stream and follow it upstream or down. Check out a Slate article with big splotch of a map showing all the tributaries of the Mississippi at the Gulf.