Looking at the 40-pound benchmark for Illinois muskies

Illinois will mark the 50th anniversary of stocking muskies in Illinois in two years, but it appears the 40-pound benchmark will continue to define greatness in Illinois muskies.

The first muskie to be verified topping 40 pounds was netted in April, 2002, during a survey at Johnson-Sauk Trail State Recreation Area near Kewanee. The 49.5 inch muskie weighed 42.9 pounds.

The 40-pound mark came back last month when biologists captured a 49.1-inch, 39.8-pound muskie during the annual spring muskie survey at Heidecke Lake, the former cooling lake in Grundy County.

“Catching a fish that size was a very exciting find, and indicates that good quality muskie can be produced in Illinois,” district fisheries biologist Seth Love emailed. “Although the catch rate did not beat last year’s, it was still fantastic at 2.2 fish/net night. We did have one net which appeared to have been tampered with, so I kindly request anglers to not disturb the nets while we are sampling. The data collected is extremely important in managing the fishery, and tampered nets bias the survey.”

Significantly, that fish was heavier than the long-standing Illinois record muskie of 38 pounds, 8 ounces. Matt Carmean caught that 50 3/4-inch muskie on April 20, 2002 below the Lake Shelbyville spillway.

Heidecke has a history of producing legal-sized muskies (48 inches) during surveys by the Illinois Department of Natural Resources, including a 48-incher in 2016, 48.6 in 2021 and 48.1 in 2022. Reports have come of anglers catching and releasing some legal-sized fish there, too.

But the heaviest honor goes to Evergreen Lake near Bloomington. In the 2005 spring muskie survey, biologist Mike Garthaus netted the heaviest verified muskie of 43-5 pounds for a 49 3/4-inch muskie.

Not surprisingly, Evergreen has a long history of big muskies (and other fish).

That includes veteran guide Thad Hinshaw (Evergreen Lake Guide Service), who has a long history of catching some of the biggest muskies in Illinois, boating what projected to be a nearly 40-pound muskie in the spring of 2020.

When he emailed confirmation of the catch, he noted, “. . . I took measurements of and did a formula on it. It came out to be 39.715 pounds.”

It was a pre-spawn fish that was 47 inches long with a girth of 26 inches.

At 47 inches long, it needed to be immediately released since Evergreen has a 48-inch limit.

Not surprisingly, the mentioned fish were all pre-spawn females caught in spring.

Those are the verified muskies of note in that 40-pound range.

There are angler reports of muskies in that range, believed because of the angler skills, photos and/or video. Rumors back nearly 20 years flowed of a 55-incher at Lake Shelbyville. Todd Clanin caught a 54-incher in the early 2000s from McMaster Lake in Knox County. An angler, who kept it quiet, caught and released a monster from Banner Marsh State Fish and Wildlife Area in Fulton County, backed by video and photos a couple years ago.

“The gist of the story is that the record could be broken,” district fisheries biologist Rob Hilsabeck said.

I am curious why 40 pounds seems the Illinois’ benchmark.

Maybe it’s because Illinois has a relatively young muskie fishery at less than 50 years old.

Don Dubin noted in his “The History of the Illinois Muskie Fishery,” “A historic event occurred in 1975, when Spring Lake in west-central Illinois, became the first official lake to be stocked with 450 tiger muskies and 235 natural muskie fingerlings.”

These decades later, I yearn to hear of an Illinois muskie pushing 50 pounds.