This data set consists of digital polygons of a constant recharge rate for the alluvial and terrace deposits along the Cimarron River from Freedom to Guthrie in northwestern Oklahoma. Ground water in 1,305 square miles of Quaternary-age alluvial and terrace deposits along the the Cimarron River from Freedom to Guthrie is an important source of water for irrigation, industrial, municipal, stock, and domestic supplies. Alluvial and terrace deposits are composed of interfingering lenses of clay, sandy clay, and cross-bedded poorly sorted sand and gravel. The aquifer is composed of hydraulically connected alluvial and terrace deposits that unconformably overlie the Permian-age Formations.

A recharge value of 2.3 inches per year is used in this report for the alluvial and terrace deposits along the the Cimarron River from Freedom to Guthrie Oklahoma. The recharge rate was estimated using a base-flow method and verified in a steady-state flow model.

The polygon boundaries and the value for constant recharge for alluvial and terrace deposits used in this data set were published in a steady-state ground-water flow modeling report. The aquifer boundaries along geological contacts were extracted from published digital geology data sets. Additional boundaries defining the geographic limits of the aquifer and areas of less than 5 feet saturated thickness were digitized from a mylar map, at a scale of 1:250,000. The maps were published at a scale of 1:900,000.

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.