Fish for Free Days allow anyone (resident or non-resident) to legally fish for Pennsylvania's most popular fish without a fishing license. No fishing license is required to fish on Pennsylvania's waterways on Saturday this year. All other fishing regulations still apply.

McConnells Mill State Park, Slippery Rock Township, just over the Butler County line into Lawrence County, will be the site of "Art in Nature" about collecting and pressing flowers at 2 p.m. Saturday, meeting at the Kildoo Picnic Area. "Guide to Geocaching" will begin at 3 p.m. Sunday at the Kildoo Picnic Area. Call the park to reserve a GPS unit. The Old Mill is open for grist mill tours at 1 and 2 p.m. Fridays, 1 and 3 p.m. Saturdays, and 2 and 4 p.m. Sundays. A new turbine has been installed in the mill, and corn grinding will be demonstrated from 11 a.m. to 3:30 p.m. Fridays and 11 a.m. to 5:30 p.m. Saturdays, from Memorial Day through Labor Day. Admission and parking are free.

Jennings Environmental Education Center, Route 528 near the intersection of Routes 8 and 173, will host a program on the basics of navigation using a global positioning unit, map and compass at 1 p.m. Saturday. This leisurely two-hour hike will help participants uncover the unique qualities of the park using old-school and modern navigation techniques. Admission is free. Call 724-794-6011 to confirm programs.

A groundbreaking for the last four-mile section of the Butler-Freeport Community Trail will begin at 10 a.m. June 7 at Franklin Field off Herman Road. A community walk will follow. For information, check the Web site: www.ButlerFreeportTrail.org.