Travel within the U.S. can take many forms, from backpacking, hiking, and camping to skiing and surfing. Some types of travel include caravanning, dog walking, backpacking, hiking, white water rafting, cross-country skiing, mountaineering, rock climbing, mountaineering and trekking, and much more. Because most countries have airline services that fly to various destinations around the globe, travel within the U.S. is quick and straightforward or may not even require a flight.