Constructed in 1930, the Old Mill boasts an iron hub which had originally been of service at Hermitage, an early manufacturing community near the Shannon village between Rome and Calhoun, Georgia, and was a gift to Berry from The Republic Mining (bauxite) and Manufacturing Company. Henry Ford had the hub moved to Berry where the wheel was rebuilt.  

The wooden overshot waterwheel, considered one of the largest in the world at 42 feet in diameter, was constructed by student workers. For many years, the mill was operated by Mr. Green Berry Goodson, a white-bearded miller who ground Berry-grown corn into meal and grits.  Water is piped directly from Berry's reservoir lake to the wheel. Once primed, the force of gravity is strong enough to push the water up the stone column and over the wheel, causing it to turn.

During 1977 the wheel was completely rebuilt as a cooperative project involving Berry students, staff, alumni and friends, and was dedicated to the memory of Mr. Gordon Keown on June 3, 1978. Mr. Keown was an alumnus of Berry, a long-time staff member and acting director of the Berry Schools from 1942-1944.

During 1985, physical plant staff and student volunteers restored the mechanism and made grinding of corn meal once again possible. The Old Mill is operated on special occasions such as Mountain Day. When available, the Oak Hill Gift Shop sells cornmeal ground at the Old Mill.