The Upper Mississippi River extends from the Mississippi River headwaters at Lake Itasca, MN to the confluence of the Ohio River at Cairo, IL - a run of approximately 1,300 miles (2,090 km). The Upper Mississippi is a wide river, except for where limestone bluffs, bedrock, and levees constrict its flow. Historically, the Upper Mississippi was a shallow river. In some locations the river averaged less than 4 feet deep. Now, of course, the main channel of the Upper Mississippi averages a minimum of 9 feet deep, thanks to the unceasing management of the United States Army Corps of Engineers. It’s a sandy river. As long as humans have attempted to move up and down the river, they have probably had to contend with ever shifting sandbars and shoals. The Army Corps uses a system of dams and dredges to scour sand from the channel. It’s a wild river. Though levees and other flood mitigation structures line the Upper Mississippi shorelines, the river continues to resist control. In spring and summer of 2019, the Mississippi River at Rock Island, IL was over flood stage for 96 days. As author Paul Schneider states in Old Man River, his ode to the Mississippi,
“at one moment the Mississippi sucks you into the mud, planting you in place like a snag. Another instant the river undermines your balance. It takes the ground out from under you, in order to tip you in and take you along with the flow. It pulls you closer to the sea, which is where you are going whether you know it or not. The Mississippi is as patient as gravity, as relentless as water” (331).
The 9-foot project was an attempt to control the Upper Mississippi in order to guarantee a viable 9-foot deep water route from the upper Midwest to the Gulf of Mexico. And so, between 1930 and 1940, between St. Paul, MN and St. Louis, MO, the Army Corps constructed 26 lock and dam structures on the Upper Mississippi River. The 9-foot project converted 552 miles of mostly free-flowing river to a “staircase of water” - a series of navigation pools that function as slack water lakes.
Two Mississippi focuses on four of these lakes, called pools, in the middle of the Upper Mississippi River lock and dam sequence. Pool 13 begins near Bellevue, IA and extends to Lock and Dam 13 near Fulton, IL. The pool represents the Upper Mississippi’s departure from the Driftless Area - a region which was not effected by ice age glaciation and is characterized by karst geology, steep ridges, and deep river valleys. Pool 13 also contains one of the downriver sections of the Upper Mississippi National Wildlife Refuge.
Pool 16 runs west from the Rock Island Rapids along a channel formed 150,000 years ago when ice sheets diverted the Mississippi at Rock Island, IL. The pool 16 dam complex at Muscatine, IA completely closes off the river at Hog Island. Pool 16 represents an “urban pool” - one that is close to a significant urban and industrial landscape.
Pool 17 sees the Upper Mississippi begin again its turn south. It is a historically productive and much-used portion of the river. Before the river was “trained” - constrained through dams and levees - pool 17 contained a large number of backwater sloughs and marshes that served as critical habitat for a variety of species. The broad floodplain in pool 17, especially north of the confluence of the Iowa River near New Boston, IL, was some of the most productive farmland on the Upper Mississippi. That land is now a part of the Port Louisa National Wildlife Refuge.
Pool 18 is the southern-most pool examined in Two Mississippi. Pool 18 begins just east of Yankee Chute in the Odessa Wildlife Management Area and winds its way past Keithsburg, IL - a town which lobbied heavily for the 9-foot project as a way to bring economic life to it’s waterfront. The results, as we will see, have been mixed.
