The U.S. Geological Survey (USGS) undertook a 5-year study beginning in 2016 to assess groundwater availability for the aquifers proximal to the Gulf of Mexico from the Texas-Mexico border to the western part of the panhandle of Florida; these aquifers are collectively referred to as the coastal lowlands aquifer system. This study is one of several regional groundwater availability studies being done as part of the USGS Water Availability and Use Science Program. Groundwater from the coastal lowlands aquifer system is used mainly for public, irrigation, and industrial supply. During the first two years of the study, the team developed an updated conceptual model of the hydrogeologic framework of the coastal lowlands aquifer system, and in support, a defining compilation of hydrogeologic data. By referencing the data in this compilation, extents of the coastal lowland aquifers were able to be updated and digitized. This data release contains the shapefiles representing the surficial extents of the respective aquifers within the coastal lowlands: the Chicot aquifer, Evangeline aquifer, Burkeville Confining Unit, Jasper aquifer, and Catahoula to the top of the Vicksburg-Jackson confining unit.