USGS Water-Year Summary for Site 12340500

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	Available Parameters
	00010 Temperature, water(Mean,Max.,Min.)
	00060 Discharge(Mean)
	00095 Specific cond at 25C(Max.,Mean,Min.)
	63680 Turbidity, Form Neph(Min.,Mean,Max.)
	80154 Suspnd sedmnt conc(Mean)
	80155 Suspnd sedmnt disch(Mean)

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Water year 2024: 2024-10-01 to 2025-09-30

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USGS Water-Year Summary 2024

12340500 CLARK FORK ABOVE MISSOULA, MT

LOCATION - Lat 46°52'36.35", long 113°55'55.63" referenced to North American Datum of 1983, in NW 1/4 NW 1/4 NW 1/4 sec.19, T.13 N., R.18 W., Missoula County, MT, Hydrologic Unit 17010204, on right bank 0.2 mi downstream from county road bridge, 2.8 mi east of Missoula, 3.0 mi downstream from Blackfoot River, and at river mile 361.6.

DRAINAGE AREA - 6,021 mi².

REVISIONS HISTORY - WSP 1042: 1936. WSP 1152: 1942. WSP 1246: 1929-30; 1935, drainage area. WSP 1316: 1932-33.

SURFACE-WATER RECORDS

PERIOD OF RECORD - March 1929 to current year. Monthly discharge only for some periods, published in Water Supply Paper (WSP) 1316.

GAGE - Water-stage recorder. Elevation of gage is 3,198.30 ft, referenced to the National Geodetic Vertical Datum of 1929 (levels by U.S. Army Corps of Engineers). Prior to May 27, 1929, nonrecording gage at site 0.22 mi upstream at different datum. May 27, 1929, to July 13, 2018, at site 225 ft upstream at same datum.

REMARKS - Diversions for irrigation occur upstream from station.

EXTREMES OUTSIDE PERIOD OF RECORD - Flood in June 1908 reached a discharge of 48,000 ft³/s, provided by The Montana Power Company.

WATER-QUALITY RECORDS

PERIOD OF RECORD - Water years 1969-71, 1977-83, 1986 to current year. Water years 1969-71 samples collected 3.4 miles downstream from gaging station.

PERIOD OF DAILY RECORD -

WATER TEMPERATURE: June 1977 to September 1983, February 2002 to September 2002.
TURBIDITY:  April to September 2007.
SUSPENDED-SEDIMENT DISCHARGE: July 1986 to April 1987, June 1988 to January 1996, March 1996 to 
March 2003, August 2003 to current year.

REMARKS -

EXTREMES FOR PERIOD OF DAILY RECORD -

WATER TEMPERATURE: Maximum, 22.5°C, Aug. 7, 8, 1983, July 13-15, 2002; minimum, 0.0°C on many days 
during winter periods.
TURBIDITY:  During period of seasonal collection, maximum, 55 FNU, May 4, 2007; minimum, 1.0 FNU, 
July 21-24, 2007.
SEDIMENT CONCENTRATION: Maximum daily mean, 1,060 mg/L, May 20, 2008; minimum daily mean, 1 mg/L, 
on many days.
SEDIMENT LOAD: Maximum daily, 46,400 tons, May 20, 2008; minimum daily, 1.6 tons, Dec. 27, 1992.

EXTREMES FOR CURRENT YEAR - SEDIMENT CONCENTRATION: Maximum daily mean, 95 mg/L, February 16, 2016; minimum daily mean, 1 mg/L, Several days in July 2016. SEDIMENT LOAD: Maximum daily, 1,390 tons, April 24, 2016; minimum daily, 4.4 tons, July 5-7, 2016.