Deliver Benefits to the Public

Discovering a piece of history

Photo: man stands in tall prairie grass and points to features of huge boulder. Boulder is as tall as he is. Two people are watching.
Midewin volunteer Keith Graham points out telling details of a 19-ton prehistoric boulder along Henslow Trail, Midewin National Tallgrass Prairie. Photo courtesy Penny Vanderhyden.

Visitors to the Midewin National Tallgrass Prairie say they discover something new with each experience. Now, they can get up close to a 19-ton boulder that dates back to glacial times. The boulder is located just off the Henslow Trail, north of Explosives Road (west side of U.S. Highway 53), south of Iron Bridge.

Research suggests that this location is consistent with where glacier movement would have likely deposited the boulder. The boulder was likely pushed here by glacial activity thousands of years ago possibly from north of the Wisconsin border.

Midewin ecologist Bill Glass spotted the rock in the South Patrol Road Prairie and noticed its potential geological and historical significance. Midewin staff and volunteers worked together to move the rock to a place where more people can experience it, and now the rock is situated along the popular Henslow Trail.

The Henslow Trail is accessible on foot, bike or horseback from 4 a.m. to 10 p.m. daily. Trail maps are available in the Midewin Welcome Center and at the Ranger Trailer.