LOCATION.--Lat 43° 35'21", long 112° 03'29" (NAD27), in NE1/4 NW1/4 SW1/4 sec.13, T.3 N., R.37 E., Bonneville County, Idaho Falls North quad., Hydrologic Unit 17040201, on right bank 2.5 mi upstream from Idaho Falls Municipal Power Plant, 5.5 mi north of Idaho Falls, and at mile 803.

DRAINAGE AREA.--9,536 mi².

PERIOD OF RECORD.--November 1982 to September 1987 (discontinued).

GAGE.--Water-stage recorder. Datum of gage is 4,700.00 ft above NGVD of 1929, levels by US Geological Survey. November 1982 to September 1983, at datum 30.94 ft lower. April 1984 to September 1987, auxiliary water-stage recorder approximately 2 mi downstream from base gage at head of island above Idaho Falls Powerplant at NGVD of 1929.

REMARKS.--Some regulation by Jackson Lake, Palisades Reservoir, Island Park Reservoir, Henrys Lake (sta 13039000), and Grassy Lake. Diversions above station for irrigation of about 700,000 acres. Considerable water leaks above station into the Snake Plain aquifer. Discharge computed from slope and conveyance of the reach between the base and auxiliary gage.

EXTREMES FOR PERIOD OF RECORD.--Maximum daily discharge, 28,900 ft³/s May 16, 1984; maximum gage height, 43.43 ft, Feb. 8, 1983, ice jam; minimum daily discharge, 2,670 ft³/s Mar. 27, 1987; minimum observed gage height, 31.19 ft, Sept. 23, 1985.