The Central Oklahoma aquifer underlies an area of about 2,900 square miles in central Oklahoma. The aquifer is in the Central Lowland Physiographic Province and consists of Garber Sandstone and the Wellington Formation, which are part of the Sumner Group of Permian age. The maximum thickness of the aquifer is about 1,000 feet with a saturated thickness ranging from 150 to 650 feet. The aquifer is an important source of water for public, domestic, and commercial use (HA 730-E). This product provides source data for the Central Oklahoma aquifer framework, including: Georeferenced images: 1. i_27CNRLOK_bot.tif: Digitized figure of altitude contour lines representing the bottom of the Central Oklahoma aquifer. The original figure was from the Hydrologic Atlas 74, Plate 2, Figure 4 (HA_724_P2_F4). Extent shapefiles: 1. p_27CNRLOK.shp: Polygon shapefile containing the areal extent of the Central Oklahoma aquifer (OFR_96-454). The extent file contains no aquifer subunits. (Special Note) Other aquifer datasets included in the Brackish Water Project (PP1833) used the 'Ground Water Atlas of the United States' (HA 730-E) as a source for aquifer extents (Central_Oklahoma_AqExtent). This project sourced the extent from Open-File Report 96-454 (OFR_96-454) as it better matched the included top and bottom altitude of aquifer contour datasets. Contour line shapefiles: 1. c_27CNRLOK_top.shp: Contour line dataset containing altitude values, in feet reference to National Geodetic Vertical Datum of 1929 (NGVD29), across the top of the Central Oklahoma aquifer (OFR_96-454). These data were used to create the ra_27CNRLOK_top.tif raster dataset. 2. c_27CNRLOK_bot.shp: Contour line dataset containing altitude values, in feet reference to NGVD29, across the bottom of the Central Oklahoma aquifer (HA_724_P2_F4). These data were used to create the ra_27CNRLOK_bot.tif raster dataset. Altitude raster files: 1. ra_27CNRLOK_top.tif: Altitude raster dataset of the top of the Central Oklahoma aquifer. The altitude values are in meters reference to North American Vertical Datum of 1988 (NAVD88). This raster was interpolated from the c_27CNRLOK_top.shp dataset. 2. ra_27CNRLOK_bot.tif: Altitude raster dataset of the bottom of the Central Oklahoma aquifer. The altitude values are in meters reference to NAVD88. This raster was interpolated from the c_27CNRLOK_bot.shp dataset. Depth raster files: 1. rd_27CNRLOK_top.tif: Depth raster dataset of the top of the Central Oklahoma aquifer. The depth values are in meters below land surface (NED, 100-meter). 2. rd_27CNRLOK_bot.tif: Depth raster dataset of the bottom of the Central Oklahoma aquifer. The depth values are in meters below land surface (NED, 100-meter).