Henrys Fork (Snake River tributary)

Henrys Fork
Henrys Fork in eastern Idaho
Henrys Fork upper drainage
Henrys Fork (Snake River tributary) is located in Idaho
Henrys Fork (Snake River tributary)
Location of the mouth of Henrys Fork in Idaho
Location
CountryUnited States
StateIdaho
CountiesFremont County, Idaho, Madison County, Idaho
Physical characteristics
Source 
 • locationnear Island Park, Fremont County, Idaho
 • coordinates44°29′34″N 111°16′58″W / 44.49278°N 111.28278°W / 44.49278; -111.28278[1]
 • elevation6,397 ft (1,950 m)[2]
MouthSnake River
 • location
southwest of Rexburg, Madison County, Idaho
 • coordinates
43°45′10″N 111°57′28″W / 43.75278°N 111.95778°W / 43.75278; -111.95778[1]
 • elevation
4,800 ft (1,500 m)[1]
Length127 mi (204 km)[3]
Basin size3,212 sq mi (8,320 km2)[4]
Discharge 
 • locationnear Rexburg[5]
 • average2,096 cu ft/s (59.4 m3/s)[5]
 • minimum183 cu ft/s (5.2 m3/s)
 • maximum79,000 cu ft/s (2,200 m3/s)

Henrys Fork is a tributary river of the Snake River, approximately 127 miles (204 km) long,[3] in southeastern Idaho in the United States. It is also referred to as the North Fork of the Snake River. Its drainage basin is 3,212 square miles (8,320 km2), including its main tributary, the Teton River.[4] Its mean annual discharge, as measured at river mile 9.2 (Henrys Fork near Rexburg) by the United States Geological Survey (USGS),[6] is 2,096 cubic feet per second (59.4 m3/s), with a maximum daily recorded flow of 79,000 cubic feet per second (2,240 m3/s), and a minimum of 183 cubic feet per second (5.18 m3/s).[5] It is normally transcribed without an apostrophe.

The river is named for Andrew Henry,[7] who first entered the Snake River plateau in 1810. Employed by the Missouri Fur Company, he built Fort Henry on the upper Snake River, near modern St. Anthony, but abandoned this first American fur post west of the continental divide the following spring.[8]

Henrys Fork of the Snake River near Coffee Pot Rapids
Kayaking the Coffee Pot Rapids of the Henrys Fork
  1. ^ a b c "Henrys Fork". Geographic Names Information System. United States Geological Survey, United States Department of the Interior. June 21, 1979. Retrieved July 22, 2013.
  2. ^ Source elevation derived from Google Earth search using GNIS source coordinates.
  3. ^ a b "The National Map". National Hydrography Dataset high-resolution flowline data. U.S. Geological Survey. Archived from the original on March 29, 2012. Retrieved May 4, 2011.
  4. ^ a b "Upper Snake, Headwaters, Closed Basin Subbasins Plan Plan" (PDF). Northwest Power and Conservation Council. Archived from the original (PDF) on February 13, 2012. Retrieved October 12, 2011.
  5. ^ a b c "Upper Snake River basin between Irwin and Idaho Falls, Water Resources Data, Idaho, 2005" (PDF). Retrieved October 12, 2011.
  6. ^ "Gage 13056500". Retrieved October 12, 2011.
  7. ^ Rees, John E. (1918). Idaho Chronology, Nomenclature, Bibliography. W.B. Conkey Company. p. 76.
  8. ^ Shallat, Todd A.; Bentley, E. B. (1994). Snake: The Plain and Its People. Boise, ID: Boise State University. p. 125. ISBN 978-0-932129-12-3. OCLC 31689273.