When I lived in Washington State I had a CCW. I was driving through North Cascades National Park when I was pulled over for exceeding the "recommended safe speed" by a Park Ranger. When he asked if I had a weapon I said "yes, and a permit" and he ordered me out of the car and removed it from the holster. I showed him my CCW. He then got on his radio and did every check he could on both me and my weapon.
I then pointed out that though I was in a National Park, I was traveling on a STATE highway (20) with no intent to stop anywhere inside the park, my destination was outside the park boundaries, therefore I was still protected under state law.
He went back and got on the radio for another 20 minutes, came back and returned my weapon, then the cartridges, and told me only Park Rangers were supposed to have guns in the park and to "get the hell out of here".
I don't know what the law is, but I suspect if I had been clearly breaking it I wouldn't have gotten off so easy. I think his superior on the radio probably told him to let me go, probably because they were'nt sure themselves and didn't want the hassle in court.
Hey, whether I was right or not, it worked!