FreeFishFishing in Illinois: lake depth maps and where to start
Reservoirs, river backwaters and Lake Michigan. How to use Illinois lake depth maps, notable waters, and where to find the official rules.
Illinois has more fishing than many people expect: large reservoirs, the Mississippi and Illinois rivers and their backwaters, the Chain O'Lakes in the north, and the Lake Michigan shoreline in Chicago. The Illinois Department of Natural Resources publishes depth maps for many public lakes and reservoirs, which FreeFish shows on the map.
What you can fish for
Largemouth bass, crappie, bluegill and channel catfish are found throughout the state. Many reservoirs also have white bass, hybrid striped bass, walleye and saugeye, and some are stocked with muskellunge. The big rivers hold catfish, sauger and white bass. Lake Michigan offers salmon, trout and yellow perch.
Waters to know
- Rend Lake: a large southern Illinois reservoir known for crappie, bass and catfish.
- Lake Shelbyville: a central Illinois reservoir known for muskellunge, walleye and bass.
- Carlyle Lake: a big, shallow reservoir east of St. Louis with crappie, white bass and catfish.
- Fox Chain O'Lakes: a connected chain of lakes in the north with bass, walleye, muskie and panfish.
Using Illinois depth maps
Illinois reservoirs were built by damming rivers, so their depth maps show old creek and river channels winding through flats. Channel edges, points and humps near channels are prime spots, especially in summer and winter. In spring, fish move up into shallow creek arms; in fall, they follow shad back into the creeks. Our depth map guide explains how to spot these features.
On the rivers, use what you know about current breaks and seams, and watch river levels, which change quickly after rain.
Through the seasons
Spring brings crappie and bass into shallow cover in reservoirs and backwaters, and white bass make spawning runs up rivers. Summer is a great time for catfish in rivers and reservoirs, and for bass early and late in the day. Fall sees bass, crappie and white bass following shad schools. In northern Illinois, lakes like the Chain O'Lakes can freeze for ice fishing, but ice conditions vary a lot from year to year.
Before you go
Many Illinois lakes have site-specific regulations, such as special size limits, and some sites have their own rules for boats and hours. Check the official regulations linked below before you go.
Official rules
Seasons, limits and license requirements change. The official source is the state agency: Illinois fishing regulations and licenses.