This data release supports the U.S. Geological Survey Scientific Investigation Map (SIM) by Clark and others (2020) by documenting the data used to create the geologic maps and describe geologic framework and hydrostratigraphy of the Edwards and Trinity aquifers for a 442 square-mile area in northern Medina County in south Texas. The karstic Edwards and Trinity aquifers that are the subject of the SIM by Clark and others (2020) are classified as major sources of water in south-central Texas by the Texas Water Development Board (George and others, 2011). The geologic framework and hydrostratigraphy of the Edwards and Trinity aquifers largely control groundwater-flow paths and storage in northern Medina County (Kuniasky and Ardis, 2004). The data provided in this data release and the detailed maps and descriptions of the geologic framework and hydrostratigraphy in Clark and others (2020) are intended to help provide water managers information that is useful for effectively managing available groundwater resources in the study area. These digital data accompany Clark, A.K., Morris, R.E., and Pedraza, D.E., 2020, Geologic framework and hydrostratigraphy of the Edwards and Trinity aquifers within northern Medina County, Texas: U.S. Geological Survey Scientific Investigations Map 3461, 13 p. pamphlet, 1 pl., scale 1:24,000, https://doi.org/10.3133/sim3461.