Illinois River (Illinois) Fishing Guides and Conditions, Illinois

About the Illinois River (Illinois)

The Illinois River is formed at the junction of the Kankakee and the Des Plaines near Channahon and runs southwest across the state to meet the Mississippi at Grafton. It is a working navigation river, dredged and controlled by a series of locks and dams, and its character is entirely shaped by that engineering: long, slow, turbid pools separated by tailwaters where the water is fast, broken and oxygenated. The valley it runs through is wide and flat, and the river is flanked for much of its length by backwater lakes, sloughs and side channels that hold fish the main channel does not.

The fishing is a mixed warmwater bag and the tailwaters are the productive spots. Sauger stack below the lock-and-dam structures from late fall through early spring and are the most sought-after fish on the river in that window. White bass run in enormous numbers in spring and are targeted below the dams and in the tributary mouths. Channel catfish are abundant everywhere and flathead catfish reach genuinely large sizes in the deeper holes and around wing dams. Largemouth bass hold in the backwater lakes and cuts, where water clarity and vegetation are better than in the main channel.

Access is spread along the valley through state fish and wildlife areas, city ramps and the backwater complexes at Spring Valley, Hennepin and Meredosia. This is a powerboat river – the main channel is broad and commercial barge traffic is constant, which makes small-craft use a matter of route planning rather than adventure. The Valley City gauge on the lower river reads discharge and stage and is the standard reference for the reach above the Mississippi confluence; no temperature series is published there.

Access

Valley City - river access near the gauge on the lower reach, serving the water above the Mississippi confluence.
Meredosia and the state fish and wildlife area - backwater and main channel access with good largemouth and catfish water.
Beardstown and Havana ramps serve the middle river and the Emiquon and Chautauqua backwater complexes.
Starved Rock and the Marseilles lock-and-dam tailwaters are the best-known sauger and white bass spots on the upper river.
Spring Valley and Hennepin give access to the backwater lakes that hold largemouth through the summer.
Barge traffic runs the main channel constantly; stay out of the sailing line and give tows a very wide berth.
Tailwater currents below the lock-and-dam structures are strong and unpredictable when gates change - keep clear of the restricted zones.

Seasons

Spring: high and muddy through the runoff, then the white bass run below the dams and in the tributary mouths from April into May.
Summer: warm and stable. Catfishing is at its best, and the backwater lakes fish well for largemouth when the main channel is too turbid.
Fall: falling water and cooling temperatures start the sauger concentration below the dams, and catfish feed heavily through October.
Winter: sauger fishing in the tailwaters is the main draw and continues through the cold months whenever ice and river stage allow access.