In 2001, The Exploration Company announced the Sacatosa Coalbed Methane (CBM) Field in Maverick County as the first CBM field in Texas. The field is currently being dewatered from three production clusters consisting of about 7 wells each. The wells are completed by perforating the casing and applying a frac. Gas production is from coal and carbonaceous shale near the base of the Upper Cretaceous Olmos Formation in the Maverick Basin. Sandstone body geometries, abundant burrowing, and flaser-type bedding indicate a deltaic origin for these sediments. The Laramide Orogeny formed the southeast plunging Chittim Anticline, which is the dominant structural feature of Maverick Basin. Subsequent erosion removed about 4000 ft of rock exhuming bituminous coal (mean random vitrinite reflectance about 0.6%) to less than 3000 ft depth. The basal coal zone thickens from 20 ft at the outcrop to about 30 ft near the eastern boundary of Maverick County. The multiple coal beds within the coal zone are thin to moderately bedded, laterally discontinuous, and interbedded with clastic and volcanic ash partings. Desorbed gas is dry (mean C1/(C2+C3) ratio=1500) with average d13C1 of –51 per mil (range of –47 to –56) and dD of –192 per mil (range of –186 to –196). These values are indicative of gases with a biogenic to mixed thermogenic origin. Initial measurements indicate the coals are at least locally gas saturated. These same coal zones extend into Mexico where coals in the related Rio Escondido Basin reportedly contain up to 300 scf/ton of CBM.