Pennsylvania Department of Conservation and Natural Resources
http://www.dcnr.state.pa.us/

Official state government website with links to state forests and state parks.

http://www.dcnr.state.pa.us/stateparks/index.aspx
Find a state park near you. Guided group walks can be arranged.

Pennsylvania Game Commission
http://www.pgc.state.pa.us/

Pictures of wildlife and nature settings from the official PA Game Commission website.