The Madison River is a headwater tributary of the Missouri River, approximately 183 miles (295 km) long, in Wyoming and Montana. Its confluence with the Jefferson and Gallatin rivers near Three Forks, Montana forms the Missouri River. The Madison rises in Teton County in northwestern Wyoming at the confluence of the Firehole and Gibbon rivers, a location known as Madison Junction in Yellowstone National Park. It flows west then north through the mountains of southwestern Montana to join the Jefferson and Gallatin rivers at Three Forks. The Madison River, from Madison Junction in Yellowstone to Three Forks, is a fly fishing mecca for serious anglers. It is classified as a blue ribbon fishery and is one of the most productive streams for brown trout, rainbow trout and mountain whitefish. The 19 miles (31 km) of the Madison in the Yellowstone Park, although easily accessible, is not suited for beginners and offers technical dry fly and nymph fishing for rainbow and brown trout