Post by Brett Peto

This article appears in the winter 2024 issue of Horizons, the award-winning quarterly magazine of the Lake County Forest Preserves in northern Illinois.

Ice seems temporary. It melts in a glass. It disappears at a sunbeam’s touch. It ebbs with the first relief of spring. But some ice leaves deeper marks than a cold drink.

On the banks of the Fox River in the southwestern corner of Lake County, Illinois, you can see back through time. Not long ago on the 4.5-billion-year arc of Earth’s history, a wall of ice 700–2,000 feet tall covered everything in view today. There was no wide, shallow river. No trees or flowers. Only ice.

Today, 691 acres near the river’s eastern shore make up Grassy Lake Forest Preserve in Lake Barrington. The preserve features 5.6 miles of trails, six scenic overlooks, sedge meadows and mature oak woodlands. Set back less than a quarter mile from the low, forested riverfront is what looks like a medium-sized hill.

A 1.6-mile trail makes a half-spiral as it ascends the hill to an overlook with magnificent views of the Fox River. There, you can rest on a bench, watch the water flow by and ponder this …

You’re sitting on a gift from the glaciers.