Illinois’ River-based Natural Divisions: Lower Illinois River

Part 2: In the second part of our feature on the Upper Mississippi River and Illinois River Bottomlands Natural Division we explore the nearly 225-mile shoreline of the Illinois River from the mouth of the river upstream to LaSalle.

John Nelson purchased a postcard at the Kampsville Museum in the 1990s that he claims typifies the vegetation patterns noted in the U.S. General Land Office surveyors Field Notes and Plat maps from the 1820s.

“This painting represents the lower Illinois River and Mississippi River valleys and is based on interpretation of archeological studies from the Kampsville (Koster) Site on the Lower Illinois River,” Nelson, an Illinois Nature Preserves Commission Natural Areas Preservation Specialist, said. “There is an amazing level of detail in the image, from the oak-hickory woodlands on the top of bluffs with extensive hill prairies above to the exposed rock outcroppings and the river where dense forests of early successional trees dominated the most flood prone areas. In between were backwater lakes, wetlands, old side channels and tributaries. A diverse assembly of wetlands, forests, savannas and prairies were found across the valley.”

The painting also includes native people who helped shape and maintain this landscape, particularly with fire.

“Today’s hill prairies are isolated patches along some bluffs as trees have taken over in the absence of disturbance,” Nelson continued. “Imagine a fire originating on the floodplain prairie in this picture that raced up the talus slopes and into the autumnal hill prairies. It would have been a sight to behold.”

Explore the Lower Illinois River

Protected lands within the Illinois River valley between LaSalle and the mouth of the river at Grafton are many, and these sites are well known to anglers, waterfowl hunters and birding enthusiasts. Sites owned by Illinois Department of Natural Resources (IDNR) include Woodford, Marshall, Donnelly, Depue, Sanganois and Banner Marsh State Fish and Wildlife Areas (SFWA). The names of additional sites—Anderson Lake, Rice Lake, Spring Lake and Pekin Lake—recognize the historic importance of the region’s backwater lakes. IDNR manages these sites to promote wetland habitat supporting viable fish populations as well as migrating and wintering waterfowl and migrating shorebirds, and to promote bottomland hardwood forests providing habitats for critical species, such as red-headed woodpeckers, a variety of herons and egrets, barn owls, river otters, Indiana bats and gray foxes.

There’s also Chautauqua National Wildlife Refuge, a site designated Important Bird Area and Ramsar Wetland of International Importance that is managed by the U.S. Fish and Wildlife Service. In Putnam County, The Wetlands Initiative has worked to restore a backwater lake ecosystem that today is recognized as the Dixon Waterfowl Refuge and Hennepin-Hooper Lakes, an area possessing a rich diversity of life that garnered its designation as a Wetland of International Importance under the Ramsar Convention on Wetlands. Downriver and located on the west bank of the Illinois River in Fulton County, similar restoration activities undertaken by The Nature Conservancy has resulted in the creation of Emiquon Preserve. This 7,000-plus acre site is one of the largest floodplain restoration projects in the Midwest and is gaining notoriety as a spring and fall waterbird migration viewing spot.

Head down stream to the Mississippi River State Fish and Wildlife Area in Jersey and Calhoun counties. The site contains 12 waterfowl management areas—Batchtown, Calhoun, Glades, Godar-Diamond, Riprap Landing, Stump and more—but it is a location for other activities associated with riverine habitats, including fishing and birding. Wading birds, such as great egret and great blue heron, bald eagles, waves of white pelicans in the spring and fall and in recent winters trumpeter swans, are a few of species that birders may sight.

Restoration Successes

For several decades now, conservation organizations have been working at sites scattered along the Illinois River system to restore or re-create wetland and bottomland forest habitats. Let’s explore a couple of successes of note—an increase in colonial bird nesting colonies and management of lands where the federally endangered decurrent false aster is found.

Success Story: Bird Sanctuaries

Angella Moorehouse, the Natural Areas Preservation Specialist in western Illinois for the Illinois Nature Preserves Commission, cited areas of the former floodplain owned and managed by the U.S. Fish and Wildlife (Chautauqua Refuge, Emiquon Refuge, Meredosia Refuge) and Illinois Department of Natural Resources (Rice Lake, Banner Marsh, Rip Rap Landing) where the ability to control water levels has allowed for quicker habitat recovery following floods. Wading birds are one guild to benefit from this action.

“Historically, many areas along Illinois’ large rivers supported large populations of nesting waterbirds such as herons and egrets, as well as migratory waterfowl and shorebirds,” she noted. “Decline of the rookeries after Europeans settled in Illinois came in part from the harvest of breeding plumes for use in the millinery industry in the late 1800s, but pollution, flooding, breeding season disturbances, and habitat alternation and destruction also played a huge role the decline.”

Rookeries may consist of a few nesting birds constructing their platform nests in trees along a small creek to a site along a large river where thousands of birds’ nest. Most colonies occur in bottomland forests close to shallow water where the birds feed on fish, crayfish and insects. Common species found in nesting colonies in Illinois include great blue herons, egret egrets, snowy egrets, black- and yellow-crowned night-herons, little blue herons and cattle egrets, with another colonial nesting species, the double-crested cormorant, often joining the colony.

“Throughout the river valleys, wetland habitat restorations and water quality improvements have benefitted many wildlife species, including the iconic colonial wading birds,” Moorehouse continued. “Many of these sites now serve as sanctuaries where these birds can nest and forage.”

Success Story: Decurrent False Aster

The federally and state listed decurrent false aster (Boltonia decurrens) is in the heart of its range along the river stretches of this division, with large populations scattered throughout.

The OutdoorIllinois Journal story A Rare Flower Makes a Comeback explains that decurrent false aster (Boltonia decurrens) is a “rare, daisy-like flower that was only recognized as its own species in 1985, and only grows along the Illinois River, although the historic range included Illinois and Missouri. As more Illinois River floodplains were converted to farmland, the aster’s habitat was lost, and populations of this native species along with it. It was added to the federally threatened species list in 1988 and is now protected under the Endangered Species Act.”

Land managers are working to promote the regrowth of the decurrent false aster at sites throughout the natural division by recreating the conditions from the time the plant had thrived. Removal of invasive woody species, spreading decurrent false aster seeds and mimicking the river’s old natural flood cycle are among the management tools used to enhance the presence of this endangered species.

Whether you have the opportunity to 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.