Although roof styles vary, the barn type used almost exclusively in the Piney Woods is the transverse-crib barn. Henry Glassie, folk historian, has theorized that the transverse-crib barn developed in the southern Tennessee Valley. The Piney Woods settlers came from that area in large numbers. Roof styles include the gambrel and the pitched roof, but the most prevalent style is the A-roof (Figs. 30-32).