The trail passes through 30 of Wisconsin's 72 counties, from the northwestern part of the state to the Lake Michigan shoreline in the east.

[6] The western end of the trail is at Interstate State Park along the St. Croix River, which is the border between northwestern Wisconsin and eastern Minnesota.

The eastern terminus of the Ice Age Trail lies at Potawatomi State Park, on Wisconsin's Door Peninsula near the city of Sturgeon Bay.

It passes through the land of various owners, including the Wisconsin Department of Natural Resources, the Ice Age Trail Alliance, and hundreds of private citizens.

[10] The Ice Age Trail began as conservationist Ray Zillmer's idea for having an "Ice Age National Park" of 500 miles starting at St. Croix Falls, going south through Madison, northeast through the Kettle Moraine areas ending near Sturgeon Bay.

[2] The park would travel through the terminal moraine of the most recent glacier to push through Wisconsin about 10,000 years ago.

It was established by Act of Congress in 1980, in large part as a result of the efforts of Reuss, who in 1976 authored the book On the Trail of the Ice Age.

[2] The first person to backpack the entire length of the Ice Age Trail was 20-year-old James J. Staudacher of Shorewood, Wisconsin during the summer of 1979.

[2] Staudacher received maps with the proposed route and supply packages from Reuss and completed the walk at St. Croix Falls in August.

Many of the best examples of glacial features in Wisconsin are exhibited in units of the Ice Age National Scientific Reserve, most of which lie along the trail.

Birds seen along the southern part of the trail include the Acadian flycatcher, Henslow's sparrow, red-headed woodpecker or hooded warbler.