The topsoil in North Carolina varies in depth depending on the region and the type of soil. In general, the topsoil in the coastal plain region is deeper, ranging from 20 to 40 inches, while in the Piedmont and mountain regions, the topsoil is shallower, ranging from 10 to 20 inches. Some areas, particularly in the mountains, may have even shallower topsoil due to factors such as erosion and rocky terrain.