Buttermilk Campground is situated right on the wooded shoreline of Island Park Reservoir, just 30 miles from West Yellowstone. The lake offers excellent boating and fishing. The campground includes a variety of site options for tent, trailer, and RV camping (45 feet max length). Sites have picnic tables and fire pits. The campground amenities also include vault toilets, drinking water, and boat ramp. There is one site with electric hookups and one large group site. Sites start at $15 per night and can be reserved online up until 4 days ahead of arrival.