LOCATION.-- Lat 42°28'05", long 90°20'20" (NAD of 1927), in SW1/4NW1/4 sec.31, T.29 N., R.2 E., Jo Daviess County, Hydrologic Unit 07060005, at Council Hill, 3 mi upstream from mouth and 6 mi northeast of Galena.

DRAINAGE AREA.-- 20.1 mi², includes that of unnamed creek.

PERIOD OF RECORD.--

SURFACE-WATER DISCHARGE AND STAGE

DISCHARGE: October 1939 to September 1950, monthly discharge only.

PARTIAL RECORD: Annual maximum, water years 1940 to 1969.

GAGE.-- Water-stage recorder. Datum of gage is 686.59 ft above NGVD of 1929. Prior to Dec. 1, 1939, wire-weight gage at same site and datum.

REMARKS.-- Records include flow of unnamed creek which enters just downstream from the gage.

EXTREMES FOR PERIOD OF RECORD.--

SURFACE-WATER DISCHARGE AND STAGE: Maximum discharge, 16,600 ft³/s, Apr. 29, 1947, gage height, 15.30 ft (from flood marks), from rating curve extended above 1,500 ft³/s on basis of slope-area determinations at gage heights 9.33 ft and 15.30 ft and a contracted-opening determination at gage height 15.30 ft; minimum, 0.3 ft³/s, June 22, 1940, gage height, 2.14 ft.