I'll be honest I haven't read all the replies but just skimmed through them. I would take up the suggestion given of just carrying a shotgun. Remember the guy who had an unloaded, disassembled hand gun in his trunk was given 7 years in New Jersey. But I think New Jersey and other states allow people with legally owned guns to travel through their states.
The gun laws I feel in this country are confusing as they can vary by state, city, and county. Then also I would imagine that federal parks have rules on guns too?
Here is a good article that is only a few months old.
https://www.nraila.org/articles/20150101/guide-to-the-interstate-transportation
James, I want to do the same thing when my house is paid off. It will probably be another 7 years for me. Do us a favor and when you actually start your trip start a separate post about your experience. I would be interested in your trip and where you went.
Thanks