>>866421>in a state park, or car style camp grounds, you'll have to buy woodIf there's state / federal land around, just drive out there and gather up firewood (make sure you have an ORV sticker for your truck).
Bring a small chainsaw, (or manual pruning saw) a machete (to de-limb larger prices, but keep those medium-smaller branches) and an axe to split bigger chunks back at camp.