Driving across northwest Missouri and southwest Iowa earlier this week, I crossed a number of small rivers flowing westward toward the Missouri River. As is often the case, I wondered where they arose and came to suspect that it must be along the Missouri-Mississippi Divide.
Though far less spectacular than the high divides of the American West, this divide separates the watersheds of rivers flowing into the Missouri River from those flowing more directly toward the Mississippi. This line of high ground cuts across the southwestern corner of Minnesota and then runs south through western Iowa. Before reaching Missouri, the divide curves eastward across southern Iowa and then dips south and east through northeast Missouri, ending at the junction of the Mississippi and Missouri Rivers, just north of St. Louis. The southern portion of this divide passes through St. Louis and then runs south through southeastern Missouri where it eventually intersects the watershed of the Arkansas River (see The Missouri-Arkansas Divide).
This hydrologic description may be of no interest to many readers but geography buffs, such as myself, want to understand the terrain through which we travel. After all, in concert with tectonic forces and the underlying geology, rivers have sculpted those landscapes.
