Geology of Hartman Creek State Park
Nearly three-quarters of the surface of Wisconsin felt the crushing, grinding weight of thick, rock-laden ice as the Wisconsin Glacier slowly moved across our state. The glacier advanced for tens of thousands of years, covering the land completely. About 15,000 years ago, the advance slowed and finally stopped as the weather became warmer. The glacier began to melt and in a few thousand years, it was gone, leaving evidence of its passage etched in the landscape.
As it melted, the glacier dropped gigantic loads of large boulders, rocks, gravel, sand, and fine soil. The glacier dropped these materials unevenly and formed many different types of landforms such as terminal moraines, recessional moraines, kames, eskers, crevasse fills, outwash plains, ground moraines and kettle holes.
Hartman Creek State Park is located on, and between, an interesting variety of landforms of glacial origin. The eastern part of the park lies on gently rolling ground moraine and pitted outwash where the receding glacier deposited rocks, and where flowing rivers from the melting glacier deposited layers of gravel and sand.
A few miles west of the park on State Highway 54 there is another rolling, pitted outwash area upon which a few rounded hills, called drumlins, are visible. Traveling further westward along the highway through the recessional moraine and down the terminal moraine there is a very sandy, level, outwash area just south of Stevens Point, Wisconsin. This terminal moraine marks where the glacier finally stopped and began to melt back. The terminal moraine can be traced for over 500 miles across Wisconsin. The glacier is responsible for the interesting scenery in this area and throughout the state of Wisconsin. It helped create the forested, rocky hills, the level farmlands, and the unique recreation areas such as Hartman Creek State Park.