Cherilyn E. Widell
Old Mill Road Bridge
Old Mill Road, Rocky Ridge, Frederick County
The Old Mill Bridge spans Owens Creek southwest of Rocky Ridge on Old Mill Road. It is a Pratt Half-Hip through truss structure in a single span of 69' in length and 16' wide. It was built by the Pittsburgh Bridge Company, Pittsburgh, Pennsylvania, in 1882. The structure is set on two random coursed stone abutments with wing walls, and is located in a rural setting. A truss design similar to many bridges in the county, including Sixes and Fourpoint Bridges, it is important as one of the oldest dated such structures and the only one known to have been built by the Pittsburgh Bridge Company in Frederick County.
The Old Mill Bridge, although constructed of a common truss design, is representative of the 19th century iron truss bridges constructed in the state of Maryland. At one time there were over 20 companies manufacturing iron truss bridges represented in the Maryland and Virginia region.