Granite Keystone Bridge
Also known as: Granite Bridge
Why it's listed
Carrying Granite Street (Route 127) between Rockport and Pigeon Cove, this single-arch bridge was built in 1872 of dressed, coursed granite taken from the neighboring quarry. Its arch spans 65 feet and the deck is 32 feet wide. The Rockport Granite Company needed a quick way to move stone from the quarry to its piers, so a cut was dug beneath the road around 1868 and the bridge was raised over it. Jonathan Pratt of Quincy, an experienced builder of stone arches, directed the work, which took about eleven weeks. Contemporary newspapers called it one of the largest stone arches in the state. The bridge remains in original condition and still serves traffic. It was listed as a reminder of Rockport's granite industry, which supplied stone to cities along the eastern and southern coasts, and as a local example of nineteenth-century civil engineering. The nomination covers only the bridge itself.
Significance in brief: The nomination argues the bridge is a reminder of Rockport's early industrial base, tied to the granite quarrying business. It is also described as a locally significant accomplishment of late-nineteenth century civil engineering. It retains integrity of location, design, setting, materials and workmanship.
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 81000117, listed August 27, 1981. Summary generated October 2026 (model claude-sonnet-5-5, prompt v1.0-2026-10-29, confidence high).
Key facts
| Address | Granite St., Rockport |
|---|---|
| County | Essex County |
| Listed | August 27, 1981 |
| Reference number | 81000117 |
| Resource type | Structure |
| Period of significance | 1872 |
| Architect / builder | Jonathan Pratt of Quincy, Massachusetts |
| Criteria |
|
| Areas of significance | Industry, Engineering |
| Level of significance | Local |
| Status (as stated in the nomination) | Described as unaltered, in good condition, on its original site, and still functional as part of Route 127; the form checks public ownership and occupied status. |
| Acreage | 0.9 |
| Coordinates | 42.66706, -70.62535 (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 81000117.
- Nomination form (PDF, National Archives) — catalog entry
- Wikipedia article (used for cross-checking only; text not reproduced here)
- Wikidata Q5595884
- This listing as JSON
Last updated October 2026. Found an error? See the editorial policy for how to report it.