USGS Water-Year Summary 2020
06467500 MISSOURI RIVER AT YANKTON, SD
LOCATION - Lat 42°51'58", long 97°23'37" referenced to North American Datum of 1927, in SW 1/4 SW 1/4 sec.18, T.93 N., R.55 W., Yankton County, SD, Hydrologic Unit 10170101, on left bank 10 ft upstream of Meridian Highway Bridge on U.S. Highway 81, 5.2 mi downstream from Gavins Point Dam, 6.0 mi upstream from James River, and at mile 805.8.
DRAINAGE AREA - 279,500 mi². approximately.
PERIOD OF RECORD - October 1995 to current year (daily gage-height records). October 1930 to September 1995 and October 2000 to September 2011 (daily discharge). Monthly discharge only for some periods, published in WSP 1309. Gage-height records collected at same site March 1873 to November 1886, March 1905 to May 1908 (fragmentary), August 1921 to September 1950 (except winter months prior to 1932), are contained in reports of the National Weather Service.
GAGE - Water-stage recorder. Datum of gage is 1,140.20 ft above North American Vertical Datum (NAVD) of 1988. Prior to Oct. 1, 2014 gage datum at 1,139.68 ft above NGVD of 1929. Prior to Sept. 20, 1932, nonrecording gage, and Sept. 20, 1932, to Mar. 9, 1967, water-stage recorder at present site and at datum 1,159.68 ft above NGVD of 1929.
COOPERATION - Daily discharges were provided by U.S. Army Corps of Engineers from October 2000 to September 2011.