Marion Bridge
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Why it's listed
Spanning the Monongahela River at Point Marion, the Marion Bridge links Greene and Fayette Counties in southwestern Pennsylvania. It is a multiple span steel structure of Warren trusses built as a cantilever through truss, with a main span of 464 feet overall and a total length of 810 feet. The bridge dates from 1930 according to the bridge file, and it was built by the Pittsburgh & Maines Steel Company. Its design follows the suspended span cantilever type, in which two outside anchor spans and two cantilever arms support a floating central span. Engineers used this arrangement in the United States from about 1885 to reach distances that simple span trusses could not cover. Its importance rests on engineering: it is the only Warren through truss and the only cantilever through truss in the group nominated under the Commonwealth's highway bridge program. The bridge was altered in 1954, 1961 and 1969.
Significance in brief: The nomination argues the bridge is unusual as the only Warren through truss and the only cantilever through truss in the nominated group. It is described as an example of the suspended span cantilever truss type, a form widely used in the United States for major river crossings from the late nineteenth century on. The area of significance is 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 88000841, listed June 22, 1988. Summary generated October 2026 (model claude-haiku-5-5, prompt v1.1-2026-10-29, confidence low).
Key facts
| Address | LR 451 over Mon River, Point Marion |
|---|---|
| County | Fayette County |
| Listed | June 22, 1988 |
| Reference number | 88000841 |
| Resource type | Structure |
| Areas of significance | Engineering |
| Level of significance | State |
| Acreage | 0.9 |
| Coordinates | 39.73941, -79.90509 (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 88000841.
- Nomination form (PDF, National Archives) — catalog entry
- Wikipedia article (used for cross-checking only; text not reproduced here)
- Wikidata Q4710281
- This listing as JSON
Last updated October 2026. Found an error? See the editorial policy for how to report it.