The 17th annual Outdoor Extravaganza will be held Friday through Monday with base camp at Breakneck Campground on Cheeseman Road, near McConnells 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 at 9 a.m. each day. Visit www.outdoorextravaganza.org for more information and registration.

Moraine State Park will celebrate Pennsylvania Hiking Week with a moderate 2-mile dog hike at 10 a.m. Saturday starting at the Pleasant Valley Picnic Area on the South Shore. Pets must be on a leash at all times, and owners are to take waste bags. The Leave No Trace organization from Colorado will lead a 3-mile hike starting at 9:30 a.m. Saturday at McDanel's Launch on the North Shore. Call 724-368-8811.

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 host a 2-mile hike over challenging terrain conducted by the Leave No Trace organization from Colorado at 1:30 p.m. Saturday. A 1.5 mile hike featuring the geology of Slippery Rock Gorge will take place at 9:30 a.m. Sunday from the Point Parking Lot. Call 724-368-3612.