LOCATION.--Lat 43° 58'06", long 113° 44'38"(Rev.)(NAD83), in NE1/4 sec.5, T.7 N., R.23 E., Custer County, Hydrologic Unit 17040218, Mackay Reservoir quad., 500 ft upstream from confluence with east channel, and 7.5 mi northwest of Mackay.

PERIOD OF RECORD.--May 1919 to November 1959 (discontinued).

GAGE.--Water-stage recorder. Datum of gage is 6,064.46 ft above NGVD of 1929, unadjusted. Prior to May 4, 1920, at datum 0.54 ft lower. May 4, 1920 to Dec. 2, 1938, at datum 0.46 ft higher. Staff gage on Mackay Reservoir is used as an auxiliary gage during periods of backwater from reservoir.

REMARKS.--Major portion of flow is return from irrigation, seepage from river channel upstream, and discharge of large spring. For sum of surface inflow to Mackay Reservoir, see station 13125500.

COOPERATION.--At times, gage height record and discharge measurements furnished by water commissioner for Big Lost River.

EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 600 ft³/s (estimated) Aug. 11, 1936, gage height, 4.88 ft, present datum, from floodmarks; minimum discharge, 49 ft³/s Apr. 27, 1935, gage height, 1.08 ft, present datum.