Fall River (Wyoming, Idaho)

Fall River
Fall River, Yellowstone National Park, 1964
Location of the mouth of the Fall River in Idaho Show map of Idaho Fall River (Wyoming, Idaho) (the United States) Show map of the United States
Location
Country	United States
State	Wyoming, Idaho
Counties	Teton County, Wyoming, Fremont County, Idaho
Physical characteristics
Source
• location	southwest of Lewis Lake, Teton County, Wyoming
• coordinates	44°14′51″N 110°45′43″W / 44.24750°N 110.76194°W / 44.24750; -110.76194[1]
• elevation	8,872 ft (2,704 m)[2]
Mouth	Henrys Fork
• location	northeast of St. Anthony, Fremont County, Idaho
• coordinates	44°01′07″N 111°34′52″W / 44.01861°N 111.58111°W / 44.01861; -111.58111[1]
• elevation	5,046 ft (1,538 m)[1]
Length	64 mi (103 km)[3]

Fall River rises on the Madison and Pitchstone Plateaus in the southwest corner of Yellowstone National Park, Wyoming and flows approximately 64 miles (103 km)^[3] to its confluence with the Henrys Fork of the Snake River near Ashton, Idaho. Historically, the river was referred to as the Middle Fork of the Snake River^[4] or as Fall River or the Falls River by trappers and prospectors as early as the 1830s.^[5] It was officially named the Falls River by the 1872 Hayden Geological Survey, but was always called Fall River by the locals^[6] and so the U.S. Board on Geographic Names changed the official name to Fall River in 1997 at the request of Idaho authorities.^[1] The river is home to numerous waterfalls and cascades in its upper reaches.