Timber Rattlesnakes den communally in rocky outcrops and
crevices throughout most of their range, with gravid females often
gestating near denning sites. Snakes exhibit high fidelity to their
denning locations, returning to the same sites throughout their
To more accurately determine Timber Rattlesnakes’ status
and distribution in Illinois, we must identify and survey potential
den sites throughout the species’ range, from Mississippi Palisades
State Park in northwestern Illinois to the Trail of Tears State Forest
in the southern tip of Illinois.
In addition to collecting basic demographic information, we monitor emergence and ingress at hibernation sites, which will help inform the timing of management activities.