USGS Water-Year Summary 2021
14020850 UMATILLA RIVER AT WEST RESERVATION BOUNDARY, NEAR PENDLETON, OR
LOCATION - Lat 45°40'18", long 118°44'08" referenced to North American Datum of 1927, in NE 1/4 NW 1/4 sec.07, T.2 N., R.33 E., Umatilla County, OR, Hydrologic Unit 17070103, on left bank, 0.5 mi east of west line of boundary for Umatilla Indian Reservation, 1.6 mi upstream from Wildhorse Creek, 2.5 mi east of post office in Pendleton and at mile 58.3.
DRAINAGE AREA - 441 mi². revised.
PERIOD OF RECORD - October 1995 to current year.
GAGE - Water-stage recorder and crest-stage gage. Elevation of gage is 1,130 ft above NGVD of 1929, from topographic map.
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 25,000 ft³/s Feb. 6, 2020, gage height, 14.28 ft, from high-water mark; minimum discharge, 20 ft³/s Aug. 3, 4, 2007.