Overview The Dillon Field Office is unable to make reservations for you. Please call Recreation.gov (877-444-6777) to book a reservation or book online. ย Campsites are available for reservation for the Peak-Season times of May 1st through September 15th. All sites are first-come-first-serve from September 16th through April 30th.ย Trapper Springs Campground is adjacent to the lower Madison River and provides good access for camping, fishing and floating. The campground has 15 camp sites, 9 avai