It is a pet peeve of mine that many works on the Southwest make reference to its many river valleys, but do not include a reference map. This quick reference map identifies the major river valleys along which the Anasazi and their neighbors settled. If you print it out, it should fit comfortably on a notebook page.
Note that all the rivers of the area ultimately are part of three great river systems: the Colorado, emptying into the Sea of Cortez; the Rio Grande, defining the US-Mexican border and emptying into the Gulf of Mexico; and (in the case of the Canadian and Arkansas Rivers) the Mississippi system.