Catahoula Parish, Louisiana, is near the center of the Mississippi Valley syncline. Surface formations include beds of Recent, Pliocene, Miocene, Oligocene, and Eocene age. Wells drilled in this parish penetrate the Miocene Catahoula formation, the Oligocene Vicksburg formation, the Eocene Jackson formation, Claiborne group (subdivided into the Cockfield, Mount Lebanon, Sparta, and Cane River formations), and Wilcox formation. Good samples for paleontological study have been obtained from wells recently drilled, and will be of assistance in correlating the Louisiana formations with type localities in Mississippi and Alabama. No well in Catahoula Parish has been drilled into the Cretaceous, or even into the basal Eocene Midway formation. The structure is a southeast-dippin monocline with some terracing. There have been several gas blow-outs from different horizons, but no commercial gas production, and no definite showings of oil have been found.