Yellowstone National Park back country campsite 9U1 is a nice perfectly flat campsite multi-use camp(pack animals can use this site) near Mountain Ash Creek in SW Yellowstone National Park. Most of the camping area is in site of the trail, some privacy at the food storage/cooking area do to a group of trees. The trail here was the busiest spot on our trip with several backpacking groups and two sets of stock animals traveling down the trail. Site has a food area with a rock fire ring and pole to hang your food back. Plenty of flat ground all around to set up your tent. Mosquitos weren't a problem on our visit but they are present. Water can be filter from the Mountain Ash Creek about a minute away from the campsite. This site has a luxury in the back country....A PIT TOILET! Just follow the sign from the cooking area to the toilet. The pit toilet is a little of a walk from camp, but that is a good thing as it gives you plenty of privacy as the“walls” of this toilet is the forest around you. A campfire is allowed when restrictions are not in place.