McConnells Mill State Park, Slippery Rock Township, just over the Butler County line into Lawrence County, will host "Art in Nature" at 2 p.m. Saturday; meet in the courtyard of the Old Mill ready to design and create artwork. The annual Heritage Festival will take place there from 10 a.m. to 7 p.m. Sept. 27 and 11 a.m. to 6 p.m. Sept. 28. The Old Mill has a new turbine and offers demonstrations from 11 a.m. to 3:30 p.m. Fridays and 11 a.m. to 5:30 p.m. Saturdays through October. Admission and parking are free. Call 724-368-9320.

Jennings Environmental Education Center, Route 528 near the intersection of Routes 8 and 173, will host a 90-minute guided walk to discuss "Ferns: Beauty Without Bloom" beginning at 2 p.m. Sunday. A Healthy Hike is planned for 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 "Who Let the Dogs Out?" at 10:30 a.m. Saturday. Join the park naturalist at the Pleasant Valley picnic area on the South Shore of Moraine for a moderate two mile hike with canine friends, followed by a doggie swim in Lake Arthur. Pets must be on a leash at all times. "Explore Off Shore" at 2 p.m. Saturday; meet the park naturalist at the Pleasant Valley launch on the South Shore. Participants may take their own kayak, or borrow one of Moraine's kayaks. To reserve a kayak or register, call the park office at 724-368-8811. Participants who use park kayaks must be at least 12 years old. An adult must accompany those participants who are younger than 18.