LOCATION.--Lat 42°50'36.6", long 91°24'04.1"
  referenced to North American Datum of 1927, in NW 1/4 SE 1/4 NW 1/4
  sec.26, T.93 N., R.5 W., Clayton County, IA, Hydrologic Unit
  07060004, on left bank 5 ft downstream from bridge on State Highway
  13 in Elkader, 100 ft upstream from French Hollow Creek, and 39.1 mi
  upstream from mouth. (map)
  DRAINAGE AREA.--903 mi2.
  SURFACE-WATER RECORDS
  PERIOD OF RECORD.--Discharge records from August 2001 to current
  year.
  GAGE.--Water-stage recorder. Datum of gage is 694.93 ft above
  National Geodetic Vertical Datum of 1929.