USGS Water-Year Summary 2024

12338300 NORTH FORK BLACKFOOT RIVER ABOVE DRY GULCH, NEAR OVANDO, MT

LOCATION - Lat 46°58'46.18", long 113°05'31.87" referenced to North American Datum of 1983, in NW 1/4 SW 1/4 SW 1/4 sec.11, T.14 N., R.12 W., Powell County, MT, Hydrologic Unit 17010203, on right downstream wingwall of the county road bridge, 0.8 mi upstream from Dry Gulch, 3.2 mi southeast of Ovando, and at river mile 2.5.

DRAINAGE AREA - 310 mi².

REVISIONS HISTORY - The datum was revised on January 21, 2025 because the previous NAVD88 datum was found to be in error by the Level III GNSS survey that was performed by Pioneer Technical Services, Inc. on October 15, 2020. 

SURFACE-WATER RECORDS

PERIOD OF RECORD - October 1997 to October 2017, July 2018 to current year.

GAGE - Water-stage recorder. Datum of gage is 4,070.84 ft (GNSS III survey by Pioneer Technical Services), referenced to North American Vertical Datum of 1988 (NAVD88). Prior to January 21, 2025, the datum of the gage was reported as 4,060 ft above NAVD88, interpolated from topographic map. Prior to August 29, 2018 at site 400 ft upstream and 4.00 ft lower datum, but also reported as 4,060 ft above NAVD88.  

REMARKS - Numerous diversions for irrigation occur upstream from station.

EXTREMES OUTSIDE PERIOD OF RECORD - Flood of June 8, 1964 reached a discharge of 11,800 ft³/s, from slope-area measurement of peak flow, as determined at North Fork Blackfoot River near Ovando (station 12338000), 9 mi upstream. Flood of May 22, 1948 reached a discharge of about 4,380 ft³/s, from slope-area measurement of peak flow at same site.

WATER-QUALITY RECORDS

PERIOD OF RECORD - September 1995 to September 2013.

PERIOD OF DAILY RECORD - WATER TEMPERATURE: April 2001 to September 2002.

REMARKS -  

EXTREMES FOR PERIOD OF DAILY RECORD - WATER TEMPERATURE: Maximum 17.5°C, Aug. 6 and 7, 2001; minimum, 0.0°C, several days in February and March 2002.