This parish is located in the oil- and gas-producing North Louisiana syncline. A brief discussion is given of rocks of Permian(?) to Recent age from well data, published cross sections, and a short season of field work. Only the Upper Jurassic is present, but there is a thick section of Cretaceous rocks, one Paleocene group and two Eocene groups. The Cook Mountain Formation is at the top in about 70 percent of the parish. Of the 33 formations encountered, 7 produce oil or gas in Lincoln Parish, and 18 in north Louisiana.