Hi Gang: I was curious about that, so I went to the PA Game Commission website and found these interesting tidbits. They also list what you can and can not do, but there is nothing specific to geocaching. This comes from Title 58. I can't find the section 722 that is refered to in the text...
(17) Engage in an activity or event involving more than ten persons, which may conflict with the intended purposes or uses as defined in section 722 of the act (relating to use of property), or poses a potential environmental or safety problem.
(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.
(21) Except on Sundays, be present on State game lands from November 15 through December 15 inclusive when not engaged in lawful hunting or trapping and fail to wear a minimum of 250 square inches of daylight fluorescent orange-colored material on the head, chest and back combined or, in lieu thereof, a hat of the same colored material. The material shall be worn so it is visible in a 360° arc. Persons using shooting ranges are exempted from this requirement.
If anyone finds anything else out, please post....Johnny