Atherton Bridge
Why it's listed
Atherton Bridge is a single-span iron pony truss built in 1870 where Bolton Road crosses the Nashua River in Lancaster, Massachusetts. The town paid $4,000 for it, and it was the first iron bridge in Lancaster. The structure has eight truss panels, a 72-foot span and an 18-foot width, and it rests on large granite block abutments. It is not a patented Post truss, but it borrows many Post features, including diagonal compression members that incline toward the center, riveted dual tension rods and Phoenix Columns. The bridge was named for the nearby Atherton family, descendants of an early signer of Lancaster's 1653 incorporation petition. It is valued as one of only two surviving examples of this truss type known to the Historic American Engineering Record, along with the nearby Ponakin Bridge. Several compression members have worked loose from their fittings, and the bridge has been closed to traffic for several years. It sits in open flood plain.
Significance in brief: It was Lancaster's first iron bridge and sits on one of the town's main roads into Lancaster. It uses many features of the Post truss and is one of only two surviving examples known to the Historic American Engineering Record, the other being the nearby Ponakin Bridge. Together the two bridges represent an important era in American engineering.
Machine-generated summary. This summary was generated by a language model from the official nomination document and has not been reviewed line by line by an editor. It may contain errors. Check the source document before relying on any detail. Source: nomination document (PDF) · National Archives catalog entry. NRHP reference 79000377, listed September 19, 1979. Summary generated October 2026 (model claude-sonnet-5-5, prompt v1.0-2026-10-29, confidence high).
Key facts
| Address | Bolton Rd., Lancaster |
|---|---|
| County | Worcester County |
| Listed | September 19, 1979 |
| Reference number | 79000377 |
| Resource type | Structure |
| Period of significance | 1800-1899 |
| Architectural style | Pony truss with Post truss features |
| Areas of significance | Engineering, Transportation |
| Level of significance | National |
| Status (as stated in the nomination) | Closed to traffic for several years because several compression members are loose from their fittings; listed in good condition and owned by the town. |
| Acreage | 0.3 |
| Coordinates | 42.44471, -71.67188 (NPS GIS) |
What listing means for this property
For a publicly owned building or structure, listing mainly matters when federal funds, permits or licences are involved: projects then go through Section 106 review so effects on the property are considered. Listing also strengthens applications for preservation grants and, for leased income-producing uses, can enable the federal rehabilitation tax credit.
General information, not legal or tax advice. Rules change; confirm with your State Historic Preservation Office or a qualified adviser.
Sources and further reading
- National Park Service, National Register of Historic Places database (snapshot May 2026), reference 79000377.
- Nomination form (PDF, National Archives) — catalog entry
- Wikipedia article (used for cross-checking only; text not reproduced here)
- Wikidata Q4813590
- This listing as JSON
Last updated October 2026. Found an error? See the editorial policy for how to report it.