A conveyor belt carrying salt inside the Morton Salt, Inc., operation. The Morton Salt, Inc., facilities are at Fairport Harbor on the Grand River in Lake County, Ohio. Ohio's rock-salt deposits are confined to the Salina Group of the Silurian Geologic Period. The F unit of the Salina Group is the principal salt-bearing unit in Ohio and is further subdivided into four units. The F1 unit is mined at Fairport Harbor by Morton Salt, Inc. The underground mine is operated on a room and pillar system that leaves central pillars of salt to hold up the structure. The image was taken by Ralph J. Berhagen in 1961.