McConnells Mill State Park, in Lawrence County, encompasses 2,546 acres of the spectacular Slippery Rock Creek Gorge. The park is open from sunrise to sunset, year-round.

Glacial History

If you stood at the Cleland Rock Vista (see the map for location and below for a photograph) 200,000 years ago, you would be standing on a ridge at a drainage divide. Water to the north flowed north and water to the south flowed south. If you stood at the same location about 140,000 years ago, you would be standing at the edge of a small lake dammed by several hundred feet of ice. The ice was the edge of a continental glacier that covered most of North America north of Cleland Rock. The glacier dam created small Lake Prouty by Cleland Rock. To the north was larger Lake Watts (modern Lake Arthur is a small recreation of Lake Watts) and further north was giant Lake Edmund.

Eventually Lake Prouty spilled over the ridge near Cleland Rock and began carving Slippery Rock Creek Gorge. As the glacier retreated, Lake Watts drained into the channel, enlarging and deepening the gorge, then Lake Edmund swiftly poured into the channel, scouring the gorge to over 400 feet deep. When the glacier finally retreated back to the north, Slippery Rock Creek Gorge was so deep that streams that normally flowed north, now flowed south, as the streams do today. The swift erosion of the gorge created its swift water and the many boulders that offer great challenges to modern whitewater boaters.

Which Rock is Slippery Rock?

Slippery Rock Creek is 49 miles long and full of slippery rocks, yet is named for one exceptionally slick rock below the Armstrong Bridge. It is believed that an Indian trail forded the creek at a shelf of sandstone near a natural oil seep, which made the rock exceptionally slippery, and gave its name to the creek, a town, a university, a rock formation and many local businesses. In the late 1800s, oil wells briefly flourished in the valley, but the oil was swiftly invaded by groundwater and the wells were abandoned. The oil wells drained the oil seep and the Slippery Rock is no longer covered in oil.

Slippery Rock Gorge Natural Area

The 930-acre Slippery Rock Gorge was designated a National Natural Landmark by the U.S. Department of the Interior in 1974 and became a State Park Natural Area in 1998. The steep-sided gorge contains numerous rocky outcrops, boulders, old growth forest, waterfalls and rare plants. Cleland Rock Vista is a great place to view the gorge.

Also part of the natural area, Hells Hollow has a wide array of wildflowers, waterfalls and habitats in addition to what can be found in the Slippery Rock Creek Gorge. A one-half-mile hiking trail leads to a cascading waterfall and an old limekiln.

No Camping: Camping is not available in the park. Information on nearby private campgrounds is available at the Moraine State Park office.