 Oil and gas exploration in the county began in the 1950s, with the largest fields being the 1969 Fitzpatrick and Wipff, and the 1970 Burr.The coal industry of Maverick County is located along a section of the Olmos Coal Formation immediately north of Eagle Pass.Mining operations developed by Dolch at Dolchburg and by the Olmos Coal, Coke, and Oil Company at Olmos were the largest coal producers in Texas around the turn of the 20th century.