GCS provides the oil and gas industry with quality structure maps and data files to aid in the exploration of oil and gas. Beginning in East Texas, through Louisianna, Arkansas, Mississippi, Alabama and Florida, GCS has systematically built and updated base maps, developed correlation networks, and correlated logs in order to produce accurate mapping services. From the correlated log data GCS constructed a computerized formation top data file. This file has grown into the largest and most used data file in the area. All wells on the GCS bases are hand spotted by our experienced staff. The logs have been correlated by our geological staff which has maintained the same quality standard established in 1968. GCS currently maintains four areas of structure map coverage. The formation top file has grown to over 130,000 wells. GCS is continually updating and expanding both the structure map and data file coverage.