Kettle Moraine State Forest—Northern Unit: Butler Lake Hiking Trail Professional Guide
Detailed Trail Description from our Guidebook
"Despite the name of the trail, much of this trek is spent on the back and slopes of Parnell Esker in the forest south of the lake. For 1.3 miles of its length, the park’s trail actually joins the Ice Age Trail, both heading out and on the final return, while passing a water-filled kettle and ending with a nice view of the namesake lake from the top of a moraine.
What spans this park and the hike itself might appear to be a moraine, but the long, narrow mound of glacial till you see here heading southwest is actually an esker, part of the 4-mile Parnell Esker, to be exact."