Illinois hunters have long associated the state's largest bucks with bottomlands beside the Mississippi and Illinois. County comparisons using the proprietary Trophy Index do not support that belief. For all 102 counties, distance between the county center and whichever river is closer bears essentially no relation to the index (correlation +0.05). For counties no farther than 20 miles from either river, the mean is 49.9. In the 20 to 50 mile band, it is 50.3; beyond 50 miles, it is 50.4. The highest ranks span the distance groups. Among the ten counties leading the index, two, Will and Cass, are no farther than 20 miles from either river; three fall in the 20 to 50 mile band; five lie beyond 50 miles. Edgar is farthest away, at 118 miles.
KEY FINDINGS
- For the full set of 102 counties, river distance and Trophy Index scores have almost no correlation (r = +0.05). Trophy production shows no tendency to track proximity to either the Mississippi or the Illinois.
- Among counties no farther than 20 miles from either the Mississippi or the Illinois, the mean Trophy Index is 49.9. The mean reaches 50.4 beyond 50 miles. These index results show no advantage for river proximity.
- Illinois's leading Trophy Index counties span the distance groups. Of the ten at the top, two, Will and Cass, are no farther than 20 miles from either the Mississippi or the Illinois; three fall in the 20 to 50 mile band; five lie beyond 50 miles. Edgar is farthest away, at 118 miles. Every band contains counties in this highest tier.
IA long-standing belief in Illinois deer hunting
Why river bottoms get the credit
For a generation, talk of giant Illinois bucks has pointed to the Mississippi and Illinois river bottoms and the wooded borders where crop fields meet floodplain. Counties along those rivers have produced famous bucks, giving that reputation a foundation. The question to test is whether counties near those rivers score higher on the Trophy Index than counties farther from them.
IINo river premium, and a mixed top ten
River counties have no overall advantage in the index
With every county included, proximity to either the Mississippi or the Illinois reveals almost nothing about Trophy Index scores. For counties no farther than 20 miles from these rivers, the mean is 49.9. In the 20 to 50 mile band, it is 50.3; beyond 50 miles, it is 50.4. Distance and index have a correlation of +0.05, indistinguishable from zero. The leading counties span the distance groups. Will County leads with 93.3; its distance is 15 miles to the Illinois River. That river starts where the Kankakee meets the Des Plaines in adjacent Grundy County. Runner-up Edgar lies 118 miles from whichever river is closer. Cass shares third place, with 10 miles separating it from the Illinois River. Among the ten leading counties, two are no farther than 20 miles from either river, three fall in the 20 to 50 mile band, and five lie beyond 50 miles.
Proximity to either the Mississippi or the Illinois fails to separate the leading Illinois trophy counties: among the ten at the top, two lie no farther than 20 miles from either river, while five lie beyond 50 miles.
Swipe table to see every column
| Distance to Mississippi or Illinois river | Counties | Mean FDR Trophy Index |
|---|---|---|
| Within 20 miles | 39 | 49.9 |
| 20 to 50 miles | 28 | 50.3 |
| More than 50 miles | 35 | 50.4 |
IIIWhat it means
Let habitat guide your hunt instead of river lore
These county results give no support to using the river-bottom reputation to favor or reject a county. Dismissing inland counties for having no large river would eliminate five among the ten Trophy Index leaders, each farther than 50 miles from both the Mississippi and Illinois. Dismissing counties beside rivers would eliminate Will and Cass, also among the ten leaders. In this index, river proximity offers no useful way to narrow the counties.
NOTES AND SOURCES
- Distances were calculated along straight lines between county centroids, taken from Census cartographic boundary polygons, and the closest points on flowlines labeled Illinois River or Mississippi River in USGS National Hydrography Dataset. Calculations date to September 2026. Starting in Grundy County, the Illinois River forms where the Kankakee meets the Des Plaines. This gives a rough indication of each county's location relative to these rivers. Its correlation with Trophy Index scores is +0.05, showing no measurable association. Checking against independent river geometry from Natural Earth led to the same finding (group averages 50.4, 49.3 and 50.7). The distances and correlation in a previous version did not match when recalculated and were replaced.
- The proprietary Trophy Index reports a derived metric on a scale running from 0 to 100. It is not a measurement from a record book, and the compilations of records behind it are not reproduced here.
Fully Drawn Research is an independent data analysis desk, not affiliated with any state wildlife agency, transportation agency, mapping provider or outfitter. Fully Drawn Research is independent and not affiliated with IDNR or any mapping provider. Rankings are analytical opinions from public and proprietary data, informational only, not hunting or investment advice. Figures current to 2024.
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