Scientists from the U.S. Geological Survey (USGS), St. Petersburg Coastal and Marine Science Center (SPCMSC), in collaboration with the U.S. Army Corps of Engineers (USACE), conducted geophysical and sedimentological surveys around Cat Island, the westernmost island in the Mississippi-Alabama barrier island chain. The objectives of the study were to understand the geologic evolution of Cat Island relative to other barrier islands in the northern Gulf of Mexico and to identify relationships between the geologic history, present day morphology, and sediment distribution. This report serves as an archive of terrestrial and marine sediment vibracores collected August 4-6 and October 20-22, 2010. Geographic Information System (GIS) data products include marine and terrestrial core locations and 2007 shoreline. Additional files included: marine and terrestrial core description logs, core photos, grain-size analysis, optically stimulated luminescence (OSL) dating and Carbon-14 dating locations and results, Field Activity Collection System (FACS) logs, and formal Federal Geographic Data Committee (FDGC) metadata (data products and downloads).