Round Valley Flour Mills
Why it's listed
Standing at the corner of Main and Greely Streets in Covelo, this weathered wooden mill processed grain for Round Valley and beyond. John S. Rohrbough developed it in 1888 on the site of an older blacksmith shop, whose east wing still survives, including a post burned with local cattle brands. In 1914 he remodeled it, adding a three-story section, a decorative false-front facade and a steam engine room, using plans drawn up in San Francisco. Inside, the original steam engine and redwood-spouted steel roller machinery remain, giving a clear picture of how such a mill worked. Regular flour production ended in 1937, and the machinery rolled barley and wheat for hog feed until the 1960s. It ran again in 1975 to process a local harvest. The form describes it as a rare survivor, with only one comparable mill known in the state. It is also tied to local literary history through a novelist's character, Ann Mitchell.
Significance in brief: The mill survives as a virtually unaltered example of a steam-powered, steel roller grain mill, with its original steam engine and redwood-spouted machinery intact. It served as Covelo's main grain processing center from about 1890 to 1940 and shipped flour to nearby communities. The form also notes its potential for historic archaeology and its place in local literary and social history.
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 80000820, listed November 10, 1980. Summary generated October 2026 (model claude-sonnet-5-5, prompt v1.0-2026-10-29, confidence high).
Key facts
| Address | Main and Greely Sts., Covelo |
|---|---|
| County | Mendocino County |
| Listed | November 10, 1980 |
| Reference number | 80000820 |
| Resource type | Building |
| Period of significance | 1888-1914 |
| Architect / builder | 1914: Engineer Spaulding; Carpenter/builder Long |
| Areas of significance | Industry, Historic - Aboriginal, Commerce, Agriculture, Architecture |
| Level of significance | National |
| Status (as stated in the nomination) | Listed as vacant and unoccupied, in fair condition. Vandalism and deterioration are noted, but the mill has been virtually unchanged since the 1914 remodeling. |
| Acreage | 1 |
| Coordinates | 39.79294, -123.25025 (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.
Noted as vacant in the nomination. Nomination documents can be decades old; current status may differ. If you are considering buying an empty listed property, read the due-diligence checklist.
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 80000820.
- Nomination form (PDF, National Archives) — catalog entry
- Wikidata Q133305591
- This listing as JSON
Last updated October 2026. Found an error? See the editorial policy for how to report it.