McConnells Mill State Park, in Lawrence County, encompasses 2,546 acres of the spectacular Slippery Rock Creek Gorge, which is a National Natural Landmark.

Created by the draining of glacial lakes thousands of years ago, the gorge has steep sides while the valley floor is littered with huge boulders. Scenic overlooks and waterfalls are popular natural attractions.

Visitors can tour a gristmill and covered bridge built in the 1800s.

Hiking at McConnells Mill State Park

11.2 miles of trails

Rugged trails traverse the gorge. Please wear appropriate clothing, including boots. For your safety and to protect the resource, please stay on the trails.

Alpha Pass Trail
1.5-mile, blue blazes, more difficult hiking

This trail is at the northern end of McConnells Mill State Park and is part of the North Country National Scenic Trail. This trail begins at the Alpha Pass scenic vista and follows the east bank of Slippery Rock Creek. There is an exit to the Point Parking Area or the trail follows the creek to the Old Mill.

Hells Hollow Trail
0.5-mile, easiest hiking

This trail begins at the Hells Hollow parking lot and follows and twice crosses Hell Run on its way to a limekiln and Hells Hollow Falls. Although the main trail is smooth and level, the section by the waterfall can be slippery.

Kildoo Trail
3-mile loop, more diffult hiking

Kildoo Trail is south of the Old Mill and begins at either end of the covered bridge. On the eastern bank of the creek the trail begins with a 400-yard paved section which leads to rocky terrain on the remaining section to Eckert Bridge.

Hikers then cross Slippery Rock Creek and continue on the west bank upstream to the covered bridge. The western section of the trail has blue blazes and is part of the North Country National Scenic Trail.

Slippery Rock Gorge Trail
6.2 miles, blue blazes, more difficult hiking

Part of the North Country National Scenic Trail, Slippery Rock Gorge Trail begins jointly with Hells Hollow Trail at the Hells Hollow parking lot. The Gorge Trail splits off just before the second footbridge.

The first two miles of the trail follows the upper Hell Run Valley. The rest of the trail follows the Slippery Rock Creek Gorge north for just over four miles to Eckert Bridge.

At about the 3.5-mile point, the trail descends into the deepest part of the gorge. This broad alluvial flood plain is known as Walnut Flats.

The trail then becomes more difficult, traversing very steep terrain. At the five-mile point, the trail crosses uplands then drops back down to creek level and follows along the creek bank to Eckert Bridge.

Hikers should allow a minimum of six hours to hike to Eckert Bridge and back. This is not a loop trail. If you only plan a one-way trip, please set up a shuttle.

Picnicking at McConnells Mill State Park

The Kildoo Picnic Area is adjacent to the parking area at the northern end of the gorge near the Old Mill. A steep trail leads down to the Old Mill. Picnic tables, charcoal, grills, and restrooms are available.

This activity or structure is ADA accessible. Located in the Kildoo Picnic Area, the ADA-accessible Kildoo Pavilion can accommodate up to 50 people. It can be reserved up to 11 months in advance for a fee. If unreserved, the pavilion is available on a first-come, first-served basis.

Wildlife Watching at McConnells Mill State Park

Glacial History
If you stood at the Cleland Rock Vista 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 re-creation 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.

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 rapid erosion of the gorge created its swift water and exposed the many boulders that offer great challenges to modern whitewater boaters.

Whitewater Boating at McConnells Mill State Park
Whitewater boating is permitted on Slippery Rock Creek. Slippery Rock Creek is a Class II to IV river, depending on the water level. Whitewater craft are not available for rent in the park.

Spring and fall are the best times for boating.

Boaters generally start from Rose Point (US 422 bridge) outside of the park boundary and finish at Eckert Bridge, covering 2.5 miles with a mandatory portage around the dam at the Old Mill. From the Eckert Bridge, boaters can extend their trip an additional 3.5 miles to the Harris Bridge. The total trip from Rose Point to Harris Bridge is approximately 6 miles.

All whitewater boaters on Slippery Rock Creek enter at their own risk. They must learn to recognize natural dangers and understand that injury and death are a possibility when boating.

CAUTION: It is illegal to “run” the dam. Boaters must stay at least 50 feet downstream of the boil at the base of the dam.

Fishing at McConnells Mill State Park

Fishing is permitted anywhere along Slippery Rock Creek with the exception of the dam structures.

The best fishing is for trout and bass. Trout are stocked several times throughout the season.

There is a fly fishing only, catch and release area by Armstrong Bridge.

Pennsylvania Fish and Boat Commission regulations and laws apply.

Hunting at McConnells Mill State Park

During established seasons, many acres are open to:

Hunting
Trapping
Training of dogs
Common game species are:

Grouse
Deer
Turkey
Rabbit
Squirrel
Hunting woodchucks, also known as groundhogs, is prohibited. Dog training is only permitted from the day following Labor Day through March 31 in designated hunting areas.

Climbing and Rappelling at McConnells Mill State Park

Two climbing and rappelling areas are available to properly equipped and experienced climbers.

The Rim Road Climbing Area is across the creek from the Old Mill.

The more advanced and rugged area is in the vicinity of Breakneck Bridge.

Numerous accidents have occurred in this area resulting in serious injuries. Please exercise extreme caution when climbing or hiking in these areas.

Climbing and rappelling is prohibited from the bridges, rock areas along park roads, or any other areas outside of the two designated climbing areas.