Hadley Parabolic Bridge
Why it's listed
Spanning a deep, wooded ravine over the Sacandaga River, this iron bridge carries Corinth Road between Hadley and its neighbor across the water. Built in 1895 by the Berlin Iron Bridge Company for the Town of Hadley at a cost of $6,000, it has an overall length of 181 feet and rests on rough-cut stone abutments and a single pier. A short pony truss meets a 136-foot lenticular truss, a design patented by engineer William O. Douglas of Binghamton in 1878 and 1885. Such bridges were once common across New York and New England, but the Douglas truss proved too flexible and was made for only about fifteen years. This semi-deck example is the only one known to survive in the state. The timber deck was later replaced, and in 1972 the structure was braced with steel cables and narrowed to fourteen and a half feet. It still serves light vehicles.
Significance in brief: The nomination calls it the only known surviving semi-deck lenticular iron truss bridge in New York State. Its larger span uses the lenticular or "parabolic" truss patented by William O. Douglas in 1878 and 1885, a design that fell out of use after a brief period of popularity. It is also an important example of late nineteenth-century iron bridge-building and transportation technology.
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 77000981, listed March 25, 1977. Summary generated October 2026 (model claude-sonnet-5-5, prompt v1.0-2026-10-29, confidence high).
Key facts
| Address | CR 1, Hadley |
|---|---|
| County | Saratoga County |
| Listed | March 25, 1977 |
| Reference number | 77000981 |
| Resource type | Site |
| Period of significance | 1800-1899 (specific date 1895) |
| Architect / builder | Berlin Iron Bridge Co. |
| Areas of significance | Engineering, Transportation, Invention |
| Level of significance | State |
| Status (as stated in the nomination) | Open to vehicular traffic of three tons or less after reinforcement in 1972; owned by the Town of Hadley and listed as occupied and in use as a transportation structure. |
| Acreage | 0.9 |
| Coordinates | 43.31392, -73.84499 (NPS GIS) |
What listing means for this property
Sites (archaeological sites, battlefields, landscapes) are often listed with a restricted address to protect them from looting or disturbance. Listing is honorary for private owners; federal undertakings on or near the site go through Section 106 review, and state laws may protect burials and artefacts regardless of listing.
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 77000981.
- Nomination form (PDF, National Archives) — catalog entry
- Wikipedia article (used for cross-checking only; text not reproduced here)
- Wikidata Q5637981
- This listing as JSON
Last updated October 2026. Found an error? See the editorial policy for how to report it.