The 16th annual Outdoor Extravaganza, sponsored by the Butler Outdoor Club, takes place this weekend. Base camp is Breakneck Campground near McConnells Mill and Moraine state parks. Activities include biking, hiking, canoe and kayak trips, a float raft trip, horseback riding, sailing and rappelling. Activities begin 9 a.m. Friday through Monday. Leaders and instructors meet guests at the campground. Call 724-526-5407 or visit the website www.outdoor extravaganza.org.

Jennings Environmental Education Center, Route 528, Brady Township, plans summer programs for groups of children ages 4 and 5, 6 to 8 and 9 to 12. Concurrent sessions are planned at Moraine State Park. Jennings is open 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.

Moraine Preservation Fund will conduct summer cruises on its Nautical Nature pontoon boat from 1 to 3 p.m. Saturdays and Sundays from Saturday through Oct. 28. There also are Wednesday Night Pizza Cruises that begin at 5 p.m. An Eco-Tour Paddle is set for 9 to 11:30 a.m. Sunday. Beginner instruction is not included. The minimum age for solo kayaks is 12. Meet at Porters Cove. Cost is $27. Register at www.ventureoutdoors.org. Monday is a fish for free day from 7 a.m. to 9:30 p.m. Anyone can legally fish without a fishing license. Call 724-368-8811.

McConnells Mill State Park, Slippery Rock Township, Lawrence County, has opened the historic gristmill and it will remain open through October. Hours are 11 a.m. to 4 p.m. Saturdays and Sundays. Admission is free. Call 724-368-3612.Western Pennsylvania Conservancy has a Friday deadline for registration for its annual river sojourn on June 9, with a canoe trip along the northern Youghiogheny River. Cost is $65, which includes meals, canoe rental, shuttle service, T-shirt and programs. Call 724-471-7202, Ext. 5110.Star parties, sponsored by the Amateur Astronomers Association of Pittsburgh, will start at about 8:40 p.m. Friday and Saturday at Nicholas E. Wagman Observatory, Deer Lakes Regional Park, Frazer Township, Allegheny County. A Venus Transit party is planned for 6 to 8:50 p.m. June 5. The star parties are held weather permitting. Admission is free. Donations are accepted for the costs of operation. Call 724-224-2510.