Note DCNR and Pa Game Commission lands are not one and the same. They have different rules. Inaddition some areas around lakes are owned by the Pa Fish Commission. Still more rules..
The rule the guy might be talking about is:
Pa Game Commission
§ 135.2. Unlawful actions
(6) Remove or attempt to remove any manmade or natural object except wildlife and fish lawfully taken. Objects which may not be removed include animals, rocks, minerals, sand and historical or archaeological artifacts.
And
(2) Plant, gather, cut, dig, remove or otherwise injure plants or parts thereof, including trees, shrubs, vines, flowering plants, cultivated crops, mushrooms and fruits of berry-producing plants.
or
(19) Use State game lands for any personal, organizational or commercial purpose other than the intended use as defined in section 722 of the act.
I guess someone could read all the above and say "NO" to geocaching....:>(
For the list see:
http://www.pacode.com/secure/data/058/chap...chap135toc.html
