My question involves criminal law for the state of: Wyoming

My friend and I were driving in Grand Teton National Park. We were in his car and he was driving. We were pulled over for speeding. The police officer claimed our eyes were glossy and searched the car. He found 3 pipes and one set of rolling papers. He found no marijuana. We both received possession charges. I have a few questions. 1. Because we were in a national park does that mean this is a federal offense? 2. None of the pipes belonged to me, can I get my charge dropped? 3. Any other advice on the matter would be greatly appreciated.