Twenty Years of Illinois Harvest

The headline (Illinois deer harvest is down about 15% since 2005) hides the shape of the last twenty years. Harvest did not slide steadily; it fell to a sharp 2013 trough, then partially recovered. Running underneath is a disease front that keeps widening: chronic wasting disease has spread from a handful of counties to 28.

A 15% decline over twenty years sounds like slow erosion. It wasn't. Harvest held near 180,000 through the late 2000s, then dropped hard into a 2013 trough of 128,572 (roughly 30% below the 2005 level in a few seasons) before climbing back to 156,338 by 2024. The Illinois herd of 2024 is smaller than 2005's, but it is not in free-fall; it found a floor and rose off it.

The more consequential trend isn't in the harvest total. It's in the disease map. CWD, confined to a handful of northern counties in the mid-2000s, is now in 28 counties with prevalence around 9.2%, and it continues to move south. That expansion is why antlerless harvest stays elevated even where hunters want more deer: reducing local density is the primary tool for slowing transmission. The count of deer taken under CWD-season provisions reflects that effort, but it is a noisy gauge: it swings with changing check-station and sampling rules, not disease prevalence directly.

Harvest totals answer to weather and permits. The disease front answers to biology. It is the pressure that hasn't turned around.

Underneath the total, the method mix shifted steadily. Archery accounted for about 35% of the statewide kill in 2005; by 2024 it was 47%: a rise that held straight through the 2013 trough and the recovery, largely independent of the total. Firearm harvest is still the larger share, but the long trend is unmistakably toward the bow: a longer season, expanding crossbow access, and a growing base of archery hunters. For anyone reading county harvest data, the implication is practical: an increasing fraction of the pressure now arrives weeks before the firearm portions, and the archery split is itself a signal of how a county is hunted.

A statewide V-curve is an average of 102 very different trajectories. The western Golden Triangle counties fell far harder than 15% (Working Paper 06); several east-central counties barely moved. In our record, the number of counties reporting CWD-season harvest widened from 5 in 2005 to 18 in 2024: an in-data echo of the official spread to 28 detection counties. The useful unit of analysis in Illinois is the county, not the state, which is why the same twenty-year record produces the wide dispersion documented in the County Report (Working Paper 01).