LOCATION.--Lat 43° 58', long 113° 44' (NAD27), in NW1/4 sec.4, T.7 N., R.23 E., Custer County, Hydrologic Unit 17040218, Mackay Reservoir quad., is the location of four gaging stations on tributaries to Mackay Reservoir, and 7.5 mi northwest of Mackay.

DRAINAGE AREA.--766 mi².

PERIOD OF RECORD.--May 1919 to November 1959 (discontinued). Prior to October 1952, published with records of Big Lost River (west channel) above Mackay Reservoir, near Mackay (sta 13124000).

REVISED RECORDS.--WSP 1287: 1919-21.

REMARKS.--Records are the sum of discharges obtained at gaging stations on Big Lost River (east and west channels) and Warm Spring Creek (east and west channels) above Mackay Reservoir, near Mackay. Channels are interconnected above respective gaging stations, and combined flow represents practically the entire surface flow which enters Mackay Reservoir.

EXTREMES FOR PERIOD OF RECORD.--Maximum daily discharge, 2,760 ft³/s June 12, 1921; minimum daily, 75 ft³/s May 10-12, 1935.