The Eagle Ford shale formation in South Texas runs from the US-Mexico border north of Laredo in a narrow band extending northeast for several hundred miles to just north of Houston. It is located directly below the Austin Chalk. The average thickness of the Eagle Ford shale is about 475 feet. The more active part of the region is mainly in McMullen, Maverick, Dimmit, La Salle, Karnes, Live Oak, and Atascosa counties. The formation produces both natural gas and oil, but it is the oil-producing and gas condensate areas that are hottest right now.

Houston-based Apache Corp. and EOG Resources are two of the largest lease-holders in the Eagle Ford. Other major players include Petrohawk, Swift Energy, ExxonMobil, ConocoPhillips, Murphy Oil, Chesapeake, Cabot Oil & Gas, and Pioneer Natural Resources.