Eldean Covered Bridge
No coordinates published for this listing.
Why it's listed
Spanning the Great Miami River about a mile north of Troy, Ohio, this two-span covered bridge was built in the summer of 1860 by James and William Hamilton, who operated a stone quarry near Piqua. It is 234 feet long and uses a 24-panel Long truss, an all-wooden design of boxed X's patented in 1830 and considered the first to rely on mathematical calculation. The timbers are white pine, likely shipped from Michigan by canal boat, and the diagonal plank flooring is unusual. Stone abutments and a pier carry the structure under a sheet metal roof. It is the last covered bridge in Miami County, one of four still crossing the Great Miami, and the second longest in Ohio. The county bypassed it in 1963 to preserve it as a historic site, adding a parking area and picnic shelter. Repairs were made in 1922, 1936 and the 1960s, yet its appearance has changed little.
Significance in brief: It is the last covered bridge remaining in Miami County and one of only four still spanning the Great Miami River. It is the second longest covered bridge in Ohio. It is also a fine and now rare Ohio example of the Long truss and of Civil War era 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). NRHP reference 100000868. Summary generated October 2026 (model claude-sonnet-5-5, prompt v1.0-2026-10-29, confidence high).
Key facts
| Address | Spanning Great Miami River at bypassed section of Eldean Rd. (CR 33), Troy |
|---|---|
| County | Miami County |
| Listed | — |
| Reference number | 100000868 |
| Resource type | Structure |
| Period of significance | 1860 (19th Century) |
| Architect / builder | James and William Hamilton (builders) |
| Architectural style | Long truss covered bridge |
| Areas of significance | Engineering |
| National Historic Landmark | Yes, designated December 23, 2016 |
| Status (as stated in the nomination) | Bypassed by Miami County in 1963 and preserved as a historic site with a parking area and picnic shelter; condition listed as good. |
| Acreage | 0.9 |
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 100000868.
- Nomination form (PDF, National Archives)
- This listing as JSON
Last updated October 2026. Found an error? See the editorial policy for how to report it.