Fly fishing means only artificial flies may be attached to a line for the purpose of attracting and enticing fish for take, regardless of the type of rod or line used; weights or split shot and strike indicators are permitted. Firehole Swimming Area means the section of Firehole River, approximately 2 miles south of Madison Junction adjacent to Firehole Canyon Drive, that is comprised of flat, calm water starting upstream at whitewater rapids situated between narrow cliffs and ending approximately 250 yards downstream where the flat, calm section of water becomes narrow and whitewater again. Terrain within 25 yards of the water and the trail that access the area is also included as part of the swimming area. Superintendent's Compendium - Yellowstone National Park (U.S. National Park Service)