This data set consists of digital water-level elevation contours for the Quaternary alluvial and terrace deposits along the Beaver-North Canadian River from the panhandle to Canton Lake in northwestern Oklahoma in 1977 and 1978. Ground water in 830 square miles of the Quaternary-age alluvial and terrace aquifer is an important source of water for irrigation, industrial, municipal, stock, and domestic supplies. The aquifer consists of poorly sorted, fine to coarse, unconsolidated quartz sand with minor amounts of clay, silt, and basal gravel. The hydraulically connected alluvial and terrace deposits unconformably overlie the Tertiary-age Ogallala Formation and Permian-age formations. The water-level elevations measured in 1977 and 1978 ranged from 2,260 feet above sea level in the northwest to 1,620 feet above sea level in the southwest. The water-level elevation contours were digitized from a folded paper map in a ground-water modeling report about the aquifer. The source map was published at a scale of 1:250,000.