LOCATION.--Lat 42° 47'12", long 111° 58'47" (NAD27), in SE1/4 NW1/4 sec.26, T.7 S., R.38 E., Caribou County, Hydrologic Unit 17040208, Chesterfield quad., on right bank 90 ft downstream from county bridge, 4.8 mi upstream from Pebble Creek, 3.5 mi north of Pebble, and at mile 57.8.

DRAINAGE AREA.--260 mi², approximately.

PERIOD OF RECORD.--October 1910 to August 1913, October 1968 to September 1977 (discontinued).

GAGE.--Water-stage recorder. Datum of gage is 5,301.27 ft above NGVD of 1929. October 1910 to August 1913, nonrecording gage 0.5 mi downstream at different datum.

REMARKS.--Flow regulated by Chesterfield (Portneuf) Reservoir, capacity 24,000 acre-ft, and Twenty-Four Mile Reservoir on Twenty-Four Mile Creek, capacity 685 acre-ft. Diversions above station for irrigation of about 14,000 acres, of which about 4,800 acres are irrigated by withdrawals from ground water (1966 determination).

EXTREMES FOR PERIOD OF RECORD.--Maximum discharge observed, 624 ft³/s Jan. 31, 1911, gage height, 6.00 ft, site and datum then in use; minimum, 9.0 ft³/s Aug. 23, 1977, gage height, 1.30 ft.