Identifying and Preserving Historic Bridges

Describes techniques to evaluate bridges for their historic significance under the National Historic Preservation Act of 1966. The U.S. Department of Agriculture Forest Service manages over 8,000 bridges, many of which need substantial maintenance or should be replaced. Any bridge that is 50 years old or older must be treated as if it is eligible for listing on the National Register of Historic Places unless an evaluation has determined that it is ineligible. The report is intended as a reference for evaluating Forest Service bridges for their historic significance. It includes a brief history of bridges built by the Forest Service and a summary of the different types of bridges. Some alternatives discussed for historic bridges that can no longer serve their original purpose are leaving them in place with reduced loads (such as pedestrian traffic), moving them, or reconstructing them with materials similar to those used originally. Appendixes include information on potentially historic bridges from the Forest Service’s Bridge and Major Culvert Inventory Data Base, a list of addresses and phone numbers for the State Departments of Transportation, and a glossary.