McConnells Mill State Park, Slippery Rock Township, just over the Butler County line into Lawrence County, will host the annual Heritage Festival from 10 a.m. to 7 p.m. Saturday and 11 a.m. to 6 p.m. Sunday. Period costumes, crafts, vendors, entertainment, tours of the Old Mill and its new turbine are planned. Call 724-368-9320.

Jennings Environmental Education Center, Route 528 near the intersection of Routes 8 and 173, will host a Healthy Hike from 6 to 7:30 p.m. Oct. 1. A trip to explore the Kennerdell tract of Clear Creek State Forest is planned for Oct. 11 and 12. Jennings is open from 8 a.m. to 4 p.m. weekdays and on weekends as scheduled. The trails are open daily from sunrise to sunset. Call 724-794-6011 to confirm programs.

Moraine State Park will be the site of a program on Historic Oil Well Operation from 10 a.m. to 4 p.m. Oct. 4 and 5. Call 724-368-8811 to confirm programs.