Illinois’ River-based Natural Division: Upper Mississippi River

Part 1: Our exploration of the Upper Mississippi River and Illinois River Bottomlands Natural Division starts with an exploration of nearly 338-mile shoreline of the Mississippi River, from the Illinois-Wisconsin border to its confluence with the Missouri River.

Floating down the Mississippi River from the Illinois-Wisconsin border you cast your eyes to the east and watch the Illinois riverfront landscape as you travel approximately 383 river miles southward to the confluence of the Missouri River. Directing your boat to the Illinois River, you scan both shorelines as you travel 225 river miles upstream to LaSalle. On your more than 600-mile adventure along these big rivers you will witness historic remnants, and re-creations, of the bottomland and backwater lakes, forests, wetlands, streams and grasslands that once blanketed the river floodplains.

As the miles pass, perhaps you reflect on the Native Americans and early pioneers whose lives were intimately tied to these rivers. The rivers provided transportation routes for hunting, fishing and trade. Villages built above the floodplain provided easy access to the waters for abundant fish, mussel and waterfowl food resources, and to the forested lands where they could harvest deer, wild turkey, squirrels and other game. On fertile soils corn, beans, pumpkins and other agricultural products were grown.

Welcome to the Upper Mississippi River and Illinois River Bottomlands Natural Division.

Public Lands Along the Upper Mississippi River

The corridor of public lands along the Mississippi River is linear but accounts for tens of thousands of acres open to the public. Here just a few of the many sites you may want to visit.

Near the confluence of the Mississippi and Apple rivers in Carroll County stand rock palisades—known today as Twin Sisters and Indian Head—that served as guideposts for Native Americans traveling the Mississippi River valley. In addition to a rich Native American history, the 2,500 acre Mississippi River Palisades State Park (SP) was one Illinois location where young men worked in the 1930s as members of the Civilian Conservation Corps. Their construction projects remain evident today in the park’s impressive picnic shelter and trails. In 1973 this park was designated as a National Natural Landmark, a recognition bestowed on sites that possess exceptional value as an illustration of the nation’s natural heritage and an area that contributes to a better understanding of the environment.

From Mississippi Palisades SP you can launch your boat on the backwaters of the Mississippi River and spend a day fishing, set up your campsite under stately trees or check out the opportunities to hunt deer, turkey, waterfowl and more. The wooded ravines host seasonal attractions from spring wildflowers and migratory songbirds to fall colors and wintertime eagle concentrations.

Down a gravel road that winds under a shady woodland canopy, the observant traveler will spot evidence of Hanover Bluff Natural Area, a 525-acre site owned by Illinois Department of Natural Resources and The Nature Conservancy. Blackened trees hint that a prescribed burn team has been working to ensure the survival of unique sand hill prairie, dry dolomite prairie, dolomite cliff, dry-mesic and mesic upland forest and seep springs communities. Cast your eyes up the slope and you’ll spot a high dolomite ridge that forms a valley wall of the Mississippi River.

Another remarkable site is Lost Mound National Wildlife Refuge. This Jo Daviess County site is a unit of the Upper Mississippi River National Fish and Wildlife Refuge. More about this site can be found at Upper Mississippi River National Wildlife and Fish Refuge Celebrates 100 Years.

Pool 19 of the Mississippi River

Pool 19, a 46.2 mile stretch between Lock and Dam 18 near Gladstone and Lock and Dam 19 at Keokuk, Iowa, is one of the most biologically diverse pools of the Mississippi River. A transition area upstream of the hydropower dam at Lock and Dam19, the area consists of braided side channels, backwaters and sloughs not found below the Lock and Dam.

Pool 19 Fish

“Because of the hydropower dam at Lock and Dam 19, Pool 19 is a lake-like situation,” Matt O’Hara, Illinois Department of Natural Resources (IDNR) Division of Fisheries, Mississippi River Fisheries Biologist for Pools 18-22, explained. “Within the pool you find a diversity of aquatic vegetation, including a large lotus bed, that supports invertebrates that in turn are a great food source for fish and waterfowl.”

Pool 19 may be the best largemouth bass pool on the Mississippi River because of its size and the diverse structure and habitats. Other species of note include crappie, northern pike, yellow perch and good numbers of catfish. Areas anglers may find of interest are the sloughs around Shokokin and Burlington Island and Thomson Slough above Dallas City as well as the creek mouths below Nauvoo and above Lock and Dam 19. Learn more about fishing Pool 19 at IFishIllinois.

O’Hara enthused about recent conversations regarding habitat improvement projects for Pool 19.

“A number of conservation organizations own sections of Pool 19 and are collectively discussing undertaking habitat improvements, including the creation of island barriers to decrease wind fetch and augment aquatic vegetation,” he explained. “The next few years will be an exciting time to work on the Mississippi River.”

Mussel Beds in Pool 19

According to Ray Geroff, an IDNR District Heritage Biologist, 26 species of mussels have been documented as occurring in Pool 19, including the butterfly and monkeyface mussels, both state-threatened species, and the spectaclecase, a federally endangered mussel.

“The area around Nauvoo is one of the most mussel-rich areas of the pool with acres of mussel beds,” noted Geroff.

Pool 19 is the “Diving Duck Capitol”

Sam Klimas, Waterfowl Project Manager with the IDNR Division of Wildlife Resources, maintains that the quality of the water in Pool 19 is the reason why hundreds of thousands of diving ducks utilize this section of the Mississippi River during spring and fall migrations. According to the Illinois Natural History Survey, the average peak count of ducks across the last five years on the Mississippi River has been more than 700,000. On Pool 19, the average peak for the same time period ranged from 300,000 to 400,000 ducks.

“The wide, shallow pool has excellent water quality that supports a diversity of submergent and emergent vegetation, mussels, snails and small fishes, all providing the food fuels migrating ducks need during their long journeys,” Klimas noted.

Auriel Fournier, Director of the Forbes Biological Station and an Associate Research Scientist with the Illinois Natural History Survey, noted that the fact Pool 19 is created by a hydroelectric dam, versus being just a navigational pool, changes how the water levels are managed. The ability to control water levels in this extremely long pool, its surrounding landscape and rich invertebrate community all contribute to the pool being a good place for diving ducks.

Frank Bellrose, renowned waterfowl research biologist with the Illinois Natural History Survey, flew over Pool 19 in November once during the late 1960s and reported a huge raft of 450,000 lesser scaup that extended for miles, He also noted large concentrations of canvasback, ring-necked ducks and American goldeneyes.

For more than 30 years, Pool 19 has been the location of a multi-state research project on lesser scaup. The Forbes Biological Station has partnered in this research project for many years and in 2021 accepted the leadership role for the banding program. The current work is funded by the Mississippi Flyway Council, with support from a wide range of partners.

Natural Division Also Hosts Unique Insects

The floodplains of the Upper Mississippi River and Lower Illinois River Bottomlands Natural Division support an array of unique insects known as floodplain specialists, including Nomia nortoni, or Norton’s nomia bee. Possessing neon green bands that reflect in the light, it is relatively large for a sweat bee, with males reaching 20mm or more in length with the slightly smaller females only 15-16mm long.

“We have lost a lot of our original floodplain marshes and backwaters due to the development of levees to convert the highly productive soils into croplands,” Angella Moorehouse, the Natural Areas Preservation Specialist in western Illinois for the Illinois Nature Preserves Commission, said. “As a result, this bee is relatively rare in Illinois and is currently being petitioned for state-threatened status.”

Moorehouse grew up along the shores of the Mississippi River in Hancock County and knows well the land south of Warsaw, an area that was once a sportsman’s paradise known as Lima Lake.

“All that remains of this former floodplain wetland is a linear levee of sand running along the far west edge to keep out the Mississippi River,” she explained. “I have found Norton’s nomia on this levee as well as many other more floodplain and western sand-loving species. Levee maintenance has, however, taken a toll on these insects. Large populations of ground nesting bees were buried under a foot of sand in December 2023.”

Whether you can take an extended, 600-mile boat trip along the Mississippi and Illinois rivers, or opt for multiple day trips by car, exploring sites within the Upper Mississippi River and Lower Illinois River Bottomlands Natural Division will provide glimpses into the floodplain natural communities and rich history of the region.

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Kathy Andrews Wright retired from the Illinois Department of Natural Resources where she was editor of OutdoorIllinois magazine. She is currently the editor of OutdoorIllinois Journal.