USGS Water-Year Summary 2024
06054500 MISSOURI RIVER AT TOSTON, MT
LOCATION - Lat 46°08'47.66", long 111°25'13.00" referenced to North American Datum of 1983, in NW 1/4 SE 1/4 NW 1/4 sec.36, T.5 N., R.2 E., Broadwater County, MT, Hydrologic Unit 10030101, on left bank 2.2 mi southeast of Toston, 4.8 mi upstream from Crow Creek, 7.8 mi downstream from Sixteenmile Creek, and at river mile 2,296.1.
DRAINAGE AREA - 14,641 mi².
SURFACE-WATER RECORDS
PERIOD OF RECORD - April 1890 to February 1891, April 1910 to December 1916, April 1941 to current year. Monthly discharge only for some periods, published in Water Supply Paper 1309.
GAGE - Water-stage recorder. Elevation of gage is 3,905.68 ft, referenced to the National Geodetic Vertical Datum of 1929. Prior to Dec. 20, 1916, nonrecording gages at site 2.5 mi downstream at different elevations. U.S. Army Corps of Engineers satellite telemeter is located at the station.
WATER-QUALITY RECORDS
PERIOD OF RECORD - Water years 1949-53, 1965, 1972 to current year. Sampling location moved in October 1978, from old bridge on U.S. Highway 287 at Toston, to cableway 2.4 miles upstream.
PERIOD OF DAILY RECORD -
WATER TEMPERATURE: May 1949 to June 1953, April 1973 to current year.
SPECIFIC CONDUCTANCE: April 1973 to September 1981.
SUSPENDED-SEDIMENT DISCHARGE: March 1949 to June 1953.
INSTRUMENTATION - Water temperature recorder was installed July 6, 1977.
EXTREMES FOR PERIOD OF DAILY RECORD -
SPECIFIC CONDUCTANCE : Maximum daily, 524 microsiemens per centimeter (uS/cm) at 25°C,
Mar. 4, 1978; minimum daily, 159 uS/cm at 25°C, May 28, 1979.
WATER TEMPERATURE: Maximum, 29.0°C, July 31, 1988, July 20, 1989; minimum, -0.1°C on many days during
winter.
SEDIMENT CONCENTRATION: Maximum daily mean, 670 mg/L, Mar. 22, 25, 1951; minimum daily mean, 5 mg/L,
July 12, 1951.
SEDIMENT LOAD: Maximum daily, 16,100 tons, May 5, 1952; minimum daily, 51 tons Feb. 1, 1951.