This paper presents, mainly graphically, the factors that limit the Appalachian oil and gas fields. On the west these are: (1) some of the formations that might contain oil or gas thin out or thin down; (2) especially, sandstones that serve as reservoirs are replaced by shales and limestones to leave no reservoir rocks. On the east the contributing factors are: (1) the rocks are mainly continental deposits and therefore non oil- and gas-bearing; (2) rock folding at the end of Carboniferous time distilled off any oil and gas that may have been present potentially east of the present fields or, for oil, below the present field; (3) the lines of equal pressure in the folding ran transverse to the lines of sedimentation so that in the southern Appalachians, the potentially fa orable sediments at the east were caught in the belt of intense folding and their oil and gas content lost. Historically the paper emphasizes the close relation of early oil and gas discoveries to the salt industry.