The twelfth lock on the Hocking Canal, the Sheep Pen lock, reflected Southeast Ohioans' efforts to open their region to the world during the mid-nineteenth century. Built as a guard lock, it was intended to permit slackwater navigation of the Hocking River by regulating water depths where river and canal met. Those plans were later abandoned, and the mechanism was converted to a lift lock, which raised and lowered boats as required by changes in the canal's elevation. Stretching from Carroll to Athens, the Hocking Canal opened in 1843, stimulated the growth of Lancaster, Logan, and Nelsonville, and opened the Hocking Valley to trade. Its major exports were salt, coal, and iron, while imports included goods from the East such as cloth, shoes, and dishes. The advent of railroads in the 1850s marked the beginning of the end for canals, and in 1894 the Hocking Canal was abandoned.