Moraine State Park will host its first kayak paddle of the season from 1 to 3 p.m. Sunday. Register for a specific location. An entry-level paddle is set from 9 to 11 a.m. Tuesday. Call 724-368-8811.

The 17th Annual Outdoor Extravaganza will be May 24 to 27 with base camp at Breakneck Campground on Cheeseman Road, near McConnell's Mill and Moraine state parks. Sponsored by the Butler Outdoor Club, activities will include trail, road and mountain biking, sailing, rafting, horseback riding, rock climbing, canoeing or kayaking on lakes and streams, hikes, nature walks, photography hike, geology hike, windsurfing, workshops and children's activities. Activities begin 9 a.m. each day. Visit www.outdoorextravaganza.org for more information and registration.

The Audubon Society hosts naturalist led walks at 9 a.m. Thursdays at the Succop Conservancy, 185 Airport Road, Penn Township. Call 412-963-6100 or visit www.aswp.org to register.

Jennings Environmental Education Center, Route 528, Brady Township, is accepting registration for DiscoverE summer programs for children. Call 724-794-6011.

McConnells Mill State Park in Slippery Rock Township, Lawrence County, will open the historic gristmill Saturday. Hours are 11 a.m. to 4 p.m. Fridays, Saturdays and Sundays through October. Interpretive tours of the mill, which last about 45 minutes, will be available at 1 a.m. 3 p.m. Additional tours for groups may be scheduled by calling 724-368-3612. Admission is free.Star parties will start, weather permitting, at 8:30 p.m. Friday and Saturday at Nicholas E. Wagman Observatory at Deer Lakes Regional Park in Frazer Township near Russellton in Allegheny County. Admission is free. Donations are accepted for operational costs. Call 724-224-2510 or visit www.3ap.org.