An air compressor is handy. On an Alaska trip, we stayed overnight in a large gas station parking area (miles from any campground). Start out next morning: thump, thump, thump. After two flat tires and now a third one! But careful inspection showed no flat tire. Started off a second time and again: thump, thump, thump. Doing a real detailed inspection revealed a fist-sized rock between the driver’s side duals. A nearby trucker came over with a very large crowbar. The rock wouldn’t budge. Solution: let the air out of one tire, remove the rock, fire up the generator, plug in the air pump, pump up the tire, and on our way.