This data set consists of digitized polygons of constant recharge values for the Rush Springs aquifer in western Oklahoma. This area encompasses all or part of Blaine, Caddo, Canadian, Comanche, Custer, Dewey, Grady, Stephens, and Washita Counties. For the purposes of modeling the ground-water flow in the Rush Springs aquifer, Mark F. Becker (U.S. Geological Survey, written commun., 1997) defined the Rush Springs aquifer to include the Rush Springs Formation, alluvial and terrace deposits along major streams, and parts of the Marlow Formations, particularly in the eastern part of the aquifer boundary area. The Permian-age Rush Springs Formation consists of highly cross-bedded sandstone with some interbedded dolomite and gypsum. The Rush Springs Formation is overlain by Quaternary-age alluvial and terrace deposits that consist of unconsolidated clay, silt, sand, and gravel. The Rush Springs Formation is underlain by the Permian-age Marlow Formation that consists of interbedded sandstones, siltstones, mudstones, gypsum-anhydrite, and dolomite beds (Mark F. Becker, written commun., 1997). The parts of the Marlow Formation that have high permeability and porosity are where the Marlow Formation is included as part of the Rush Springs aquifer. The Rush Springs aquifer underlies about 2,400 square miles of western Oklahoma and is an important source of water for irrigation, livestock, industrial, municipal, and domestic use. Irrigation wells are reported to have well yields greater than 1,000 gallons per minute (Mark F. Becker, written commun., 1997). Mark F. Becker created some of the recharge data set by digitizing parts of previously published surficial geology maps. There are 87 recharge rates, ranging from 0.09 to 3.20 inches per year, used by Mark F. Becker (written commun., 1997) to simulate the ground-water flow in the Rush Springs aquifer. The average estimated recharge is about 2 inches per year or about 7 percent of the average annual precipitation. The recharge rates were based on stream discharge measured at sites in drainage basins in the Rush Springs study area during low-flow periods in March 1989 and February 1991 (Mark F. Becker, written commun., 1997). Ground-water flow models are numerical representations that simplify and aggregate natural systems. Models are not unique; different combinations of aquifer characteristics may produce similar results. Therefore, values of recharge used in the model and presented in this data set are not precise, but are within a reasonable range when compared to independently collected data.