USGS Water-Year Summary 2023
12087000 MASHEL RIVER NEAR LA GRANDE, WA
LOCATION - Lat 46°51'25", long 122°18'05" referenced to North American Datum of 1927, in NW 1/4 SE 1/4 sec.21, T.16 N., R.4 E., Pierce County, WA, Hydrologic Unit 17110015, on left bank, 50 ft downstream from State Highway 7 bridge, 1.8 mi northeast of La Grande, and at mile 3.3.
DRAINAGE AREA - 80.7 mi².
SURFACE-WATER RECORDS
PERIOD OF RECORD - October 1940 to September 1957, October 1991 to current year.
GAGE - Water-stage recorder and crest-stage gage. Datum of gage is 619.53 ft above NGVD of 1929. Prior to Oct. 1, 1957, on right bank at same datum.
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 9,520 ft³/s, Feb. 6, 2020, gage height, 7.94 ft, from rating curve extended above 6,920 ft³/s; minimum discharge, 1.35 ft³/s, Sep. 9, 2021.