McConnell’s Mill State Park encompasses 2,529 acres of the spectacular Slippery Rock Creek Gorge in Lawrence County. The park is located approximately 40 miles north of Pittsburgh, via Interstate 79, near the intersection of PA Route 19 and U.S. Route 422. McConnell's Mill State Park
In 1852, Daniel Kennedy's first gristmill on Slippery Rock Creek was destroyed by fire so he rebuilt it in 1868. Thomas McConnell bought the mill in 1875, and improved it by replacing the waterwheel with water turbines and the grinding stones with rolling mills. One of the first rolling mills in the country, it processed corn, oats, wheat and buckwheat for local customers. Sagging profits and antiquated equipment closed the mill in 1928.
In 1942, the mill and surrounding property was conveyed from Thomas H. Hartman to the Western Pennsylvania Conservancy and later to the Commonwealth of Pennsylvania with the wish that it be preserved for future generations. McConnells Mill State Park was formally dedicated in October of 1957.
One of two covered bridges in Lawrence County, it was built in 1874 and is of Howe Truss design. A registered National Historic Landmark, the bridge is on state park land but is the property of Lawrence County.