Dinosaur National Monument is located in the northwest corner of Colorado and spans the border into northeast Utah. The area is a long way from most anything. The towns of Dinosaur, Colorado and Vernal, Utah are the closest places to get gas. Coming from Colorado, Rangley is the last place with a grocery store for grabbing camping supplies.
The Echo Park campground is an amazing place to spend the night. This is a bit of a concession for those who like to camp primitively on BLM lands but worth the $8 fee to spend the night. The campground is surrounded by 500′ walls of sandstone and sits adjacent to a large bend in the at that point Green River, however the campground is withing walking distance of the confluence of the Yampa River and the Green.