Do not bring fresh fruits and veggies across into the United States from Canada. We were not forewarned and we had some food confiscated. We were confused since there were giant signs about other items you cannot bring in the USA (guns, drugs, etc.).
Cell phone service is spotty near the National Parks in the west, especially once you get away from the highways. If you are in a caravan with other cars, think about using walkie talkies to communicate while driving and while hiking.
frugaltravelbug 