Staple Bend Tunnel
Also known as: Allegheny Portage Railroad Tunnel
Why it's listed
Built between 1831 and 1833 on the Allegheny Portage Railroad in Conemaugh Township, Cambria County, Pennsylvania, the Staple Bend Tunnel runs about 900 feet through sandstone and shale beside a bend of the Little Conemaugh River. Sylvester Welch served as chief engineer, and J. and E. Appleton built it. Its horseshoe-shaped opening is about 20 feet wide and 16 feet tall at the crown. The first 150 feet at each end are lined with dressed stone, while the central 600 feet remain unlined rock marked by original drill-hole scars. Workers drilled by hand and blasted with black powder, and the tunnel was taken out of use in the 1850s. It is regarded as the first railroad tunnel in the United States. It also shows how the railroad carried canal boats over the Allegheny Mountain, linking Philadelphia with Pittsburgh at a time when trade was moving away from the Ohio and Mississippi rivers. Its construction methods and engineering reflect early American tunnel practice.
Significance in brief: The nomination argues the tunnel was the first railroad tunnel in the United States and an engineering achievement of its time. It also links the tunnel to regional trade, helping keep Philadelphia a major port by connecting it with western Pennsylvania. Its national significance is tied to the history of tunneling.
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 94001187, listed April 19, 1994. Summary generated October 2026 (model claude-haiku-5-5, prompt v1.1-2026-10-29, confidence high).
Key facts
| Address | Jct. of PA 3035 and Mineral Pt., Conemaugh Township |
|---|---|
| County | Cambria County |
| Listed | April 19, 1994 |
| Reference number | 94001187 |
| Resource type | Structure |
| Period of significance | 1831-1853 |
| Architect / builder | Sylvester Welch (Chief Engineer) / J. & E. Appleton (Builders) |
| Criteria |
|
| Areas of significance | Transportation, Engineering |
| Level of significance | National |
| National Historic Landmark | Yes, designated April 19, 1994 |
| Status (as stated in the nomination) | The eastern portal has suffered the greatest damage since the tunnel was taken out of use in the 1850s, and both portals are now sealed with concrete block walls and steel doors. The National Park Service is negotiating to purchase the tunnel, which is not open to visitors. |
| Acreage | 2 |
| Within district | Allegheny Portage Railroad National Historic Site |
| Coordinates | 40.35939, -78.85502 (NPS GIS) |
What listing means for this property
National Register listing is honorary: it recognises significance and does not restrict what a private owner may do without federal money or permits. It unlocks the 20% federal rehabilitation tax credit for income-producing buildings, state credits in many states, and Section 106 review when federal agencies are involved. See what listing means in practice.
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 94001187.
- Nomination form (PDF, National Archives) — catalog entry
- Wikipedia article (used for cross-checking only; text not reproduced here)
- Wikidata Q7482493
- This listing as JSON
Last updated October 2026. Found an error? See the editorial policy for how to report it.