USGS Water-Year Summary 2021
06090300 MISSOURI RIVER NEAR GREAT FALLS, MT
LOCATION - Lat 47°35'04.00", long 111°03'38.09" referenced to North American Datum of 1983, in SW 1/4 SE 1/4 SW 1/4 sec.11, T.21 N., R.5 E., Cascade County, MT, Hydrologic Unit 10030102, on left bank 700 ft downstream from Morony Dam, 12.6 mi northeast of Great Falls, and at river mile 2,105.4.
DRAINAGE AREA - 22,881 mi².
- WDR MT-2014: Drainage area.
PERIOD OF RECORD - May to July 1953 in Water Supply Paper 1320-B, October 1956 to current year.
GAGE - Water-stage recorder. Elevation of gage is 2,807.21 ft, referenced to the National Geodetic Vertical Datum of 1929. Prior to July 27, 1977, nonrecording gage at same site at elevation 2.00 ft higher. July 27, 1977 to May 26, 1987, at site 600 ft upstream at elevation 2.00 ft higher. October 1971 to July 27, 1977, discharges were obtained from the Montana Power Company at Rainbow Dam 7.05 mi upstream. Prior to October 1971, Foxboro meters were used for determining discharge through powerplant. Water-stage recorder on Morony Reservoir was used for determining head on taintor gates with elevation of gage at sea level (level by Montana Power Company).
EXTREMES FOR PERIOD OF RECORD - Maximum peak flow from hydrographic comparison with nearby stations. Instantaneous low flow occurred around the time of a powerplant shutdown.