Cooper Park Wetlands is an Illinois Registered Reserve located in East Peoria, just south of the McClugage Bridge. This beaver dam is close to the bank of lower Peoria Lake, and may be easily seen by walking along the sandy lake shore. The Illinois River flows through the middle of lower Peoria Lake. This photograph was taken by Mitch Lovgren.
Rock outcroppings are not uncommon along the upper Illinois River. The most impressive formations are at Buffalo Rock State Park, where this photograph was taken in 1978, and Starved Rock State Park.
Flood waters were high enough when this photograph was taken to allow a canoe to pass from Rice Lake through the surrounding forests directly to the Illinois River, about 1.5 miles away. Such large summer floods are not usually a yearly occurrence.
Bath Chute is a side channel of the Illinois River, named after the town of Bath in Mason County. It is a large, gently meandering channel adjacent to Grand Island, one of the largest islands in the Illinois River. Bath Chute offers an opportunity to experience the Illinois River's ecology, flora, and fauna in a relatively quiet backwater setting, away from the hustle and bustle of the main river.
This cenotaph and overlook are at the very top of the river bluff overlooking Chandlerville and the Illinois River valley. The Sangamon River flows just north of town, and joins the Illinois River at Beardstown, about 15 miles to the west. Below the cenotaph is a small native hill prairie, which is a surviving remnant of the extensive prairies that once existed across much of Illinois.
This photograph shows waters from the Illinois River flowing over a spillway into the south pool of Chautauqua National Wildlife Refuge. The system was designed to allow larger floods to connect the south pool with the river. Such floods during the summer, however, are detrimental to the wetland communities in the refuge because plants may be completely drowned or seed production may be hampered. If this happens, migratory birds later in the year will find less food. If mudflats are flooded over when the shorebirds are migrating, they will fly elsewhere.
Chautauqua National Wildlife Refuge is located adjacent to the Illinois River a few miles upstream of Havana, about 125 miles from the Mississippi River. Water levels within the refuge, behind the levee system, can be manipulated by a series of spillways and pumps. During years when the water levels are drawn low during the summer, parts of the refuge are completely disconnected from the river; in such areas, a rich wetland community develops, culminating with a spectacular wildflower display in September. These yellow flowers in turn draw thousands of monarch butterflys en route to their migratory destinations. From July through October, mudflats attract thousands of migrating shorebirds, and the shallow waters attract a variety of foraging herons and egrets. When the bulk of the migrating waterfowl pass through in the fall, there usually is a great abundance of food available, from seeds to invertebrates to fish.
Hill prairies, comprised of a mixture of wildflowers, grasses and shrubs, occur on steep, southwestern-facing bluff systems, mainly along major river valleys. Growing conditions for plants are tougher here than elsewhere due to the intense sunlight, rapid drainage, and drying southwesterly winds, which prevail during the midwestern summers. Periodic fires are necessary to maintain the hill prairies; without fires, trees and shrubs take over from the prairie vegetation, despite the harsh growing conditions. This small, remnant hill prairie, shown in the photograph taken at Crevecoeur Nature Preserve, is burned off every few years; even so, the surrounding forest is barely being kept at bay. The Illinois River is just beyond the base of the river bluffs.
At several areas along the river bluffs, groundwater emanates from wide expanses called seeps, eventually forming spring runs that flow into the river or to bottomland lakes. Due to the special chemical characteristics of the groundwater, unique plant communities form around the seeps in the peaty, spongy soil. The plant community at Dore Seep is considered to be of very high quality.
This double-crested cormorant colony is in a black willow woodland in the frequently flooded bottomlands of Quiver Lake, a backwater Lake connected to the Illinois River. Prothonotary warblers, red-headed woodpeckers, yellow-billed cuckoos, warbling vireos, tree swallows, and house wrens are numerous in these woods.
Businesses close to Peoria's river front were affected by the flooding Illinois River, as the river rose over the appropriately named Water Street.
This long, narrow backwater lake is just upriver from the Brussels Ferry, which provides access to Calhoun County and other sections of Two Rivers National Wildlife Refuge.
This diamicton outcropping is located on the terminal moraine of the Wisconsin glacier at Fort Crevecoeur Park, Tazewell County, on bluffs overlooking the Illinois River valley. It is a mixture of gravel and smaller grains that appear as if cemented together into a friable solid matrix. In places animals have dug small caves into the brittle solid. This photograph was taken by Mitch Lovgren.
The Havana Park District's nature center, under construction opposite the mouth of the Spoon River, is surrounded by the flooding Illinois River, as seen from campground site #7.
A variety of bottomland lakes occur along the Illinois River. These shallow lakes, from less than an acre to a few thousands acres, occur along the river's wide floodplain, by definition a flat expanse of land. Flood waters may be exchanged between the river and the bottomland lakes depending upon the various water levels of each lake and the river. Because the river's floodplain provides deep, flat, rich soil, it is ideal for farming...except when it floods. So like many rivers in the Midwest, much of the Illinois River's floodplain has been protected from the river by a system of levees. Hennepin-Hopper Lakes have been restored from farmland, but are still separated from the Illinois River by a levee system. Because of this, the lakes are fed only from groundwater, precipitation, and runoff, but not directly from river water.
[Note: For an explanation of hill prairies, see the caption for Crevecoeur Hill Prairie.]
The Hopewell Hill Prairies occur within a thriving subdivision on the Illinois River bluffs. Because most of the homes occur on flatter ground, the remnant hill prairies that occur at the Village of Hopewell have been mostly spared from development. The prairie shown in this photograph is one of the best in the state, in terms of how the vegetation resembles what hill prairies were thought to be like before European-Americans moved into Illinois.
This photograph was taken a few years before restoration of the Hennepin-Hopper Lakes. The area was a highly productive farm in 1992 and for many years before that, and is now a complex of highly productive wetlands and lakes (see other photographs in this gallery). The Illinois River is beyond the levee to the left of the trees.
Limestone cliffs capped with loess (a fine wind-blown soil) characterize much of the Illinois River valley downstream from Scott County. The bluff at this location is adjacent to the former Koster Site, one of the most important archaeological digs in North America. From evidence gathered through extensive excavations over many years, scientists have determined that humans have occupied this particular site for over 7,000 years.
A trail leads to the top of this hill prairie from the visitor's center at Pere Marquette State Park, Illinois. On a clear day, one can see the arch at downtown St. Louis, Missouri, roughly 33 miles to the southeast.
The Illinois River flows into the much larger Mississippi River after flowing 273 miles from northeastern Illinois. An archipelago of islands is located at the point of confluence, opposite the town of Grafton, Illinois. In this photograph, taken on a calm day in 1991, the Mississippi River is on the left of the islands, and the Illinois River is on the right.
This photograph was taken in April 2008, just before the trees leafed out. The opposite shore, across the Illinois River, is Bellrose Island, owned by the Havana Park District.
This photograph was taken from the Kankakee River looking northward toward its mouth. At this location, about 40 miles southwest of Chicago, the Kankakee River and the Des Plaines River join to form the Illinois River. The Kankakee Bluffs can be seen in the background. The Illinois and Michigan Canal runs along the base of the bluffs.
The Spoon River enters the Illinois River opposite the town of Havana. This photograph was taken during the Great Flood of 1993, while canoeing through the forests on Bellrose Island. During large floods of this type, it is possible to float through most of the low-lying floodplain forests.
Since this photograph was taken (2006?), the arching branch of the bur oak tree has broken off in a storm. And as a result of sustained high water during the last growing season (2008), the large lotus beds visible in the distance have disappeared.
The Peoria-Pekin metropolitan area, about a third of the way to the Mississippi River from the Illinois River's formation in northeastern Illinois, is the largest urban area along the Illinois River. Here the river flows through the Peoria lakes (upper and lower), which is a natural widening of the river made much larger and deeper by the Peoria Lock and Dam. The Peoria Pool, created by the lock and dam to facillitate river navigation, extends from the Peoria Lock and Dam to the Starved Rock Lock and Dam.
Pileated woodpeckers make rectangular-shaped holes in dead and living trees. Larger holes are used as nesting cavities by species unable to excavate their own holes, such as the tree-nesting wood duck and hooded merganser.
Located near the Cap au Gres faulted flexure, thought to have occurred during the late Mississippian geological period, as tectonic plates were colliding (North America with Europe and Africa). Source: Geology Underfoot in Illinois by Raymond Wiggers.
Big Blue Island is in the lower Illinois River, about 58 miles upstream from the Mississippi River. This photograph was taken when the river was at a low-water period during late summer, as evidenced by the steep river banks left high and dry.
Seeds from smartweed provide an important fall food source for migrating waterfowl. Several species of smartweed are quite common at the Emiquon National Wildlife Refuge, which can attract large numbers of ducks, especially northern pintails.
This photograph was taken from the top of Starved Rock in La Salle County. The section of the Illinois River behind the dam is referred to as the Starved Rock Pool; the Peoria Pool is below the dam. Gates in the dam are raised and lowered appropriately to manipulate water levels above and below the dam to maintain a navigation waterway Photograph by K.E. Barr.
The nectar of milkweed plants is an excellent energy source for insects, especially migrating butterflies such as the monarch. Swamp milkweed is a common wetland plant, blooming in the latter part of summer, at the Emiquon National Wildlife Refuge.
The gradually sloping ground at the margins of Thompson Lake have given rise to a wide band of shallow-water wetlands with emergent vegetation. This photograph was taken in April 2008 at the edge of dry land, looking northward toward the Sister Creek bluffs and Sister Creek Mound.
By the cooler months of 2007-2008, when this photograph was taken, Thompson Lake had clearly re-emerged as a permanent fixture on the floodplain landscape. This area is across the Illinois River from Havana and Chautauqua National Wildlife Refuge, and is within the approved acquisition area for the Emiquon National Wildlife Refuge, which is located just to the south. Steam from the Havana power station is visible in the right hand side of the photograph.
A sign of changing times. On the Illinois River at Havana, it has long been a common sight to see open barges transporting coal from the docks located just north of town. But only recently, the coal docks have been completely removed and the nearby generating plant closed down. Now the old coal docks property is a staging area for wind turbine components being brought in by rail and river barges.
This photograph was taken from a canoe about a mile upstream of Havana, on the Fulton County side of the river. The Illinois River is a busy commercial navigation waterway throughout the year, but such craft are slow-moving and easy to avoid. During the summer months canoeing is not a very pleasurable experience on the river because of the heavy traffic in speedboats, personal watercraft, and large cruisers. But from October through April, motorized recreational boat traffic decreases greatly, and the river is compatible with the slow, easy pace of paddling a canoe.