What is the deepest lake in Illinois?

Of the lakes with a published depth, Kinkaid Lake is the deepest at about 80 ft.

Deepest lakes in Illinois: 10 lakes ranked by depth

Which lakes in Illinois go deepest? These 10 have a published maximum depth, from Kinkaid Lake at about 80 ft down.

Deepest first

#	Lake	Deepest	Size
1	Kinkaid Lake	about 80 ft	2,750 acres
2	LaSalle Lake	about 70 ft	2,060 acres
3	Lake Shelbyville	about 67 ft	11,100 acres
4	Clinton Lake	about 60 ft	4,900 acres
5	Cedar Lake	about 60 ft	1,750 acres
6	Little Grassy Lake	about 60 ft	1,200 acres
7	Coffeen Lake	about 59 ft	1,100 acres
8	Horseshoe Lake	about 54 ft	2,400 acres
9	Peoria Lake	about 52 ft	15,500 acres
10	Lake of Egypt	about 52 ft	2,300 acres

1. Kinkaid Lake

At some 2,750 acres, Kinkaid Lake is small enough to learn in a few trips. You will find it near Murphysboro. Expect largemouth bass, spotted bass, bluegill and crappie. At about 80 ft deep, it stays cooler below the surface well into summer. Kinkaid Lake, formed by damming Kinkaid Creek in 1972, is the deepest lake in southern Illinois at about 80 feet.

Kinkaid Lake today: water temperature, bite times and the 3-D lake bed

2. LaSalle Lake

LaSalle Lake spreads over 2,060 acres. The lake is near Seneca. Walleye, muskie, white bass and striped bass are the draw. At about 70 ft deep, it stays cooler below the surface well into summer. On the 3-D map the bed has three point drop-offs and a sheltered cove: good places to start. LaSalle Lake is a cooling reservoir for the LaSalle County Nuclear Generating Station and is stocked with muskellunge and walleye.

LaSalle Lake today: water temperature, bite times and the 3-D lake bed

3. Lake Shelbyville

At 11,100 acres, Lake Shelbyville is a big lake. Expect crappie, largemouth bass, walleye and white bass. It goes down to about 67 ft. The lake bed gives you three point drop-offs and two sheltered coves to work.

Lake Shelbyville today: water temperature, bite times and the 3-D lake bed

4. Clinton Lake

At 4,900 acres of water, Clinton Lake is a good-sized lake. The lake is about 3 miles northeast of Farmer City. Expect largemouth bass, bluegill, crappie and catfish. The deepest water is around 60 ft. On the 3-D map the bed has three point drop-offs and two sheltered coves: good places to start. Clinton Lake was built in the 1970s on Salt Creek to supply cooling water to the Clinton Nuclear Power Station.

Clinton Lake today: water temperature, bite times and the 3-D lake bed

5. Cedar Lake

Cedar Lake covers 1,750 acres. You will find it about 5 miles northeast of Carbondale. The usual Illinois mix applies: largemouth bass, crappie, bluegill and catfish. At about 60 ft deep, it stays cooler below the surface well into summer. The lake bed gives you three point drop-offs and two sheltered coves to work. Cedar Lake, formed by damming Cedar Creek in 1974, supplies drinking water to Carbondale, Illinois, and has a 10-horsepower limit on boat motors.

Cedar Lake today: water temperature, bite times and the 3-D lake bed

6. Little Grassy Lake

Little Grassy Lake spreads over some 1,200 acres. The lake is near Carbondale. Expect catfish. At about 60 ft deep, it stays cooler below the surface well into summer. Its bed shows three point drop-offs and two sheltered coves worth a first look. Little Grassy Lake is a clear-water lake in the Shawnee National Forest that serves as the broodstock lake for the IDNR's state fish hatchery. The water is known for being clear: lighter line and natural colours help.

Little Grassy Lake today: water temperature, bite times and the 3-D lake bed

7. Coffeen Lake

Coffeen Lake is a reservoir of 1,100 acres. It lies near Hillsboro. Largemouth bass, spotted bass, crappie and catfish are the draw. The deepest water is around 59 ft. On the 3-D map the bed has three point drop-offs and two sheltered coves: good places to start. Coffeen Lake is a man-made lake built in the 1960s that served as a cooling reservoir for a coal power plant until it closed in 2019.

Coffeen Lake today: water temperature, bite times and the 3-D lake bed

8. Horseshoe Lake

Horseshoe Lake covers 2,400 acres of water. It lies within an easy drive of St. Louis (about 4 miles). It holds largemouth bass, bluegill, crappie and catfish. It goes down to about 54 ft. On the 3-D map the bed has three point drop-offs and two sheltered coves: good places to start.

Horseshoe Lake today: water temperature, bite times and the 3-D lake bed

9. Peoria Lake

Peoria Lake covers 15,500 acres. The lake is right by Rome. The usual Illinois mix applies: largemouth bass, crappie, bluegill and catfish. The deepest water is around 52 ft. On the 3-D map the bed has three steep ledges and an upper arm: good places to start. Peoria Lake is a wide, naturally shallow stretch of the Illinois River that has lost most of its original depth to sediment since the early 1900s.

Peoria Lake today: water temperature, bite times and the 3-D lake bed

10. Lake of Egypt

Lake of Egypt covers 2,300 acres. You will find it about 2.5 miles southwest of Goreville. It holds largemouth bass, smallmouth bass, crappie and bluegill. At about 52 ft at its deepest, it warms quickly in spring. Its bed shows three point drop-offs and two sheltered coves worth a first look. Lake of Egypt is a 2,300-acre reservoir in southern Illinois known for its largemouth bass fishing.

Lake of Egypt today: water temperature, bite times and the 3-D lake bed

The clearest of them

Little Grassy Lake is known for clear water. On a clear lake fish see a long way: lighter line, natural colours and longer casts make the difference.

Fishing deep water

In summer a deep lake splits into a warm top layer and a cold bottom; fish hold near the line between them, often 20 to 40 ft down. A depth finder, a slow troll or a jig dropped straight down finds them.