Webster Donora Bridge
Why it's listed
Steel through-truss highway bridge spanning the Monongahela River between Donora and Rostraver, carrying traffic across the Washington and Westmoreland County line. The two counties built it jointly, and the bridge was completed in 1908 by the Sofias Construction Company. It comprises five truss spans and nine girder and slab spans, with a total length of 1,531 feet. The main span is a 515-foot Pennsylvania Petit truss, the unusually long form that is the bridge's distinctive feature. Four Parker trusses complete the through-truss section, three measuring 184 feet and one 207 feet. The trusses were assembled on site from prefabricated members, including loop-welded and die-forged eyebars and riveted channels, bolted and pin-connected into their configurations. They rest on stone masonry piers. Its significance lies in its engineering, specifically the way one structure combines two truss types to suit varied site conditions. Later alterations, recorded in 1938, 1949, 1961 and 1966, have affected the fabric.
Significance in brief: The nomination describes the bridge as an unusual example of a multiple-span through truss bridge combining two different truss types. Its main span is an unusually long Pennsylvania Petit truss, supported with four Parker trusses, showing how the truss form could be adapted to varied site conditions. The nomination identifies engineering as the area of significance.
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 88000813, listed June 22, 1988. Summary generated October 2026 (model claude-haiku-5-5, prompt v1.1-2026-10-29, confidence medium).
Key facts
| Address | A 143 over Monongahela River, Donora |
|---|---|
| County | Washington County |
| Listed | June 22, 1988 |
| Reference number | 88000813 |
| Resource type | Structure |
| Architect / builder | Sofias Construction Company (builder) |
| Areas of significance | Engineering |
| Level of significance | State |
| Status (as stated in the nomination) | The form records alterations in 1938, 1949, 1961 and 1966, and notes that the bridge was reconstructed. |
| Acreage | 1.5 |
| Coordinates | 40.18415, -79.85198 (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 88000813.
- Nomination form (PDF, National Archives) — catalog entry
- Wikipedia article (used for cross-checking only; text not reproduced here)
- Wikidata Q5296804
- This listing as JSON
Last updated October 2026. Found an error? See the editorial policy for how to report it.