LOCATION.--Lat 41°21'38", long 92°58'23"
  referenced to North American Datum of 1927, in SW 1/4 SW 1/4 SE 1/4
  sec.19, T.76 N., R.18 W., Marion County, IA, Hydrologic Unit
  07100009, on right bank 0.4 mi downstream from outlet of Red Rock
  Reservoir, 2.0 mi southwest of Pella, 2.6 mi upstream from Lake
  Creek, and 138.7 mi upstream from mouth. (map)
  DRAINAGE AREA.--12,330 mi2.
  SURFACE-WATER RECORDS
  PERIOD OF RECORD.--Discharge records from October 1992 to current
  year.
  GAGE.--Water-stage recorder. Datum of gage is 600.00 ft above
  National Geodetic Vertical Datum of 1929.
  REMARKS.--Flow regulated by Lake Red Rock (station 05488100), 0.4
  mi upstream.