While drivers license requirements are generally reciprocal in North America, vehicle requirements are not. This could pertain to things like brakes required on trailers, if you can carry passengers in trailers, axle weight restrictions, towing doubles, over-all combined vehicle length, and so on. These are state-by-state in the USA, and province by province in Canada. So if you carry the kids in the fifth wheel, or tow doubles or triples so all the toys come along, or tow over 65' in over-all length, might want to do some checking.
Brian