The project rehabilitated a 4-span stone arch bridge for use as a trail connection in Montgomery County. A.D. Marble served as the historic consultant and provided above-ground cultural resources clearance and ensured the rehabilitation followed the Secretary of the Interior’s Standards for the Treatment of Historic Properties. In 2023, the project won a Preservation Pennsylvania Historic Preservation award in the construction category for rehabilitation.

Services and Problems Solved:

• Above-ground cultural resources clearance included background research to help understand the bridge’s construction and guide the rehabilitation of the bridge. Close coordination with the engineers and designers ensured that the character-defining features of the bridge were preserved during the rehabilitation, while ensuring the structure is sound and secure for decades to come.
• A.D. Marble led the cultural resources coordination with the Pennsylvania State Historic Preservation Office (PA SHPO) and the United States Army Corps of Engineers (USACE), Philadelphia District, who was the lead federal agency. Coordinated with the engineers throughout the design and construction phases to ensure any issues or changes to the original rehabilitation plan met the Secretary of the Interior’s Standards for the Treatment of Historic Properties.
• Prepared a Determination of Effects Memo that outlined why the bridge is historically significant as a contributing element to the National Register-listed Sunrise Mill, the existing conditions of the bridge, the proposed rehabilitation plan, and assessed the potential effects of the rehabilitation project to the bridge and Sunrise Mill. The memo determined the project would have No Adverse Effect to the Sunrise Mill Bridge and Sunrise Mill, and the PA SHPO concurred with that determination.
• To accommodate cyclists and other trail users the bridge’s existing parapets needed to be raised to meet current safety standards. Working in partnership with the PA SHPO and USACE, A.D. Marble proposed a unique solution using a wood railing system that could be easily maintained by Montgomery County, met the increased height required by current safety standards, and met the Secretary of the Interior’s Standards by not impacting historic material.