OVERVIEW
Tilghman Island is a historic community located in Talbot County on Maryland's eastern shore. It is separated from the mainland by a small body of water known as Knapps Narrows and is accessible via the Knapps Narrows bridge. Built in 1934, the the state-owned Knapps Narrows Bridge is the only overhead counterweight bascule span bridge in the state. Ninety five feet long and 20 feet wide, the structure is extremely important to the state of Maryland and Tilghman Island, both for its unique engineering and its historic and aesthetic relationship to the island. Consequently, the State Historic Preservation Officer (SHPO) determined that the bridge was eligible for listing on the National Register of Historic Places (NRHP) and was a significant contributing resource to the Tilghman Island Historic District. The district itself was also determined to be eligible for listing on the NRHP, as it is the best remaining example of the Chesapeake island community that sprung from large plantations during the 18th century.

Despite the modern houses and new developments now scattered about it, Tilghman Island is still characterized by its 19th- and early 20th-Century frame houses, and still consists of four distinct villages surrounded by open fields and ever present views of the water. Moreover, the island remains a community of watermen and home to a large number of skipjacks.

In addition to its historical distinction, the Knapps Narrows Bridge is still heavily used, opening for boats more often than any other moveable bridge in Maryland, and more often than most bridges on the East Coast. It provides the only land access between the Tilghman Island community and the mainland.

PURPOSE & NEED
The project purpose and need were to address vehicular and pedestrian safety issues associated with the Knapps Narrows Bridge, as well as overhead clearance issues for the frequent commercial and recreational boating traffic in the area. Alternatives were developed to rehabilitate or replace the bridge to alleviate these problems and widen the constrained roadway.

CHALLENGE
The unique challenge of this project was in the development an acceptable build alternative, despite significant impacts to the bridge and the historic district. The Maryland State Highway Administration (SHA) had to convey to the regulatory agencies and the public that neither a rehabilitation alternative nor a no-build alternative would meet the project purpose and need.

A rehabilitation alternative was developed, but it was not considered feasible and prudent because it would have resulted in an adverse impact on the historic integrity of the bridge. Both alternatives would have failed to address the safety and clearance issues.

SOLUTION
As a result of coordination with citizens, local historic groups, and the Maryland Historical Trust (MHT), a replacement alternative was selected and approved (with associated mitigation measures). Although this alternative did not avoid impacts to the historic district and the historic bridge, it did meet the project purpose and need. Replacement and design of the new bridge was coordinated with the SHPO, and all efforts were made to reflect the character of the original structure (in design, not in dimension) and to maintain the integrity of the Tilghman Island Historic District.

Although the Section 4(f) process did not require specific public involvement efforts for this project, the Section 106 process did. These efforts were designed to elicit public feedback about the value of the bridge to the community. The people living on and around Tilghman Island had strong feelings about the project and viewed the bridge as a critical link to their history. Consequently, efforts were made to document the bridge's role in the lives of people in the surrounding community.

As a part of this effort, a Memorandum of Agreement (MOA) was coordinated with the SHPO. It included a provision that the bridge be documented according to the standards of the Historic American Engineering Record. (Such documentation typically includes large photographs, as-built plans, and other technical drawings for public display.) It also included a provision requiring a cultural recordation effort, in consultation with the MHT's Cultural Conservation Program, to document the experience of the tenders and users of the bridge.

As for the fate of the historic bridge, the MHT was given the opportunity to salvage and store any portion of it during demolition. After an unsuccessful attempt to market it for re-use, it was placed along the entrance of the Chesapeake Bay Maritime Museum in St. Michaels, approximately five miles from Tilgman Island.