This data set consists of digital water-level elevation contours for the alluvial and terrace deposits along the North Canadian River from Canton Lake to Lake Overholser in central Oklahoma. Ground water in approximately 400 square miles of Quaternary-age alluvial and terrace aquifer is an important source of water for irrigation, industrial, municipal, stock, and domestic supplies. The aquifer consists of clay, silt, sand, and gravel. Sand-sized sediments dominate the poorly sorted, fine to coarse, unconsolidated quartz grains in the aquifer. The hydraulically connected alluvial and terrace deposits unconformably overlie Permian-age formations. The aquifer is overlain by a layer of wind-blown sand in parts of the area. Water-level elevation contours, based on water-levels measured in 1980, were digitized from a folded paper map in a ground-water flow modeling report for the aquifer. The source map was published at a scale of 1:250,000. Water-level elevations in the alluvial and terrace deposits ranged from 1,600 feet above sea level in the northwest to 1,220 feet above sea level in the southeast.