Thanks for so many great suggestions. Nicky has no problems with riding in the truck. He LOVES it! I take him with me all the time for walks in the parks, etc. There was just something about the pop-up that made him uncomfortable. It was a tiny little pop-up that shook something fierce with every step you took. The Colby T. is bigger and is very well stabilized so that may make the difference. We are going to spend so much time hiking the trails that he will be pretty tired by the time we end up in the camper for any lenght of time. I bought him some long lasting treats to distract him when we first go in.
I also got his furminator and combed out about three dogs worth of fur. We'll do some more while we are at the park. It calms him and keeps him cooler.
I'll let you all know how it goes when we get back.