Carroll Engineering served as Prime Structural Engineer on this project to preserve and restore the historic Casselman Bridge, one of the oldest surviving bridges in the United States. When it was erected in 1813, the 80-foot-long structure was the longest single-span stone arch bridge in the country. Located within Casselman River Bridge State Park, this project involved an initial assessment of the structure to determine the repairs needed and how to perform them in the most historically sensitive way possible. CEI provided full structural designs for an evaluation and subsequent repairs to the roadway decking, stone walls, abutments, and the barrel of the bridge.