Little-Known Fact: The serpentine ridges in Kettle Moraine State Forest are called “eskers,” formed by streams traveling through tunnels at the base of glaciers 10,000 years ago.
I wanted to do some hiking in the Kettle Moraine State Forest in spring, when the trees were budding, the birds were nesting, and the bugs weren’t yet buzzing. But other commitments kept getting in the way. Then summer came, along with the poison ivy and ravenous mosquitoes, so it was early fall and peak color before I finally made the journey.
It turned out to be pretty good timing. It was a sunny Indian Summer weekend and southeast Wisconsin’s time to tout its fall finery. I couldn’t imagine a better day for a hike or a mountain-bike ride (bikes are allowed on only 23 miles of the area’s 145 miles of trails). The path was a corridor of colors. Clusters of multicolored trees surrounded ponds and streams running across the countryside. Hilltop vistas revealed quintessential dairy-land scenes: rolling hills overlaid with a patchwork of farms and dairies that stretched to the horizon.
About 10,000 years ago, this area was buried under a glacier that covered two-thirds of Wisconsin as well as most of northern North America. The giant sheet of ice advanced and retreated several times during a period of about 15,000 years. In the process, it tore up, picked up, and deposited pieces of terra firma along the way. As the glacier melted, a most unusual landscape was unveiled. Giant boulders and anomalous piles of cobbles were left among the rolling hills and ridges. Large conical hills along with dells and dales dotted the undulating countryside. Ponds and lakes filled depressions left behind.
The conical hills, called kames (some are 350 feet high), were formed by surface rivers flowing down to the ground through cracks in the ice, depositing heaps of cone-shaped debris along the way. Serpentine ridges, called eskers, were formed by streams traveling through tunnels at the base of the ice sheet. Ridges formed by sand, boulders, and cobbles when the glacier melted are called moraines.
Errant rock piles and boulders became a part of the traveling deep freeze, moving with the ice until the glacier melted and randomly deposited its cargo. Often a block of ice would be buried under the stony debris, forming a depression called a kettle. Many of Wisconsin’s lakes occupy these formations.
The edge of the glacier’s handiwork is outlined by the 1,000-mile-long Ice Age Trail, which connects the two Kettle Moraine State Forest units. Hiking possibilities in the Kettle Moraine range from rugged half-day hikes to week-long adventures. Three-sided shelters are interspersed along the Ice Age Trail, and several are in the Kettle Moraine forests.
In winter months, some of the trails are groomed for cross-country skiing. I was told the silence of a snow-fallen trail in the light of a full moon easily rivals the lively fall colors and pretty spring and summer flowers. I can’t wait to see for myself.