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Rancho Guenoc

Mexican land grant in California

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General referenceInterpretive dossier study · Crown Archives visual atlas
Record originEnglish Wikipedia
Text licenseCC BY-SA 4.0
Source revisionJul 20, 2026
Entity authorityQ7290996 ↗
Source-derived summary

Rancho Guenoc (/ˈranʧo ɣeˈnok/ RAN-cho GWE-nok) was a 21,220-acre (33 sq mi) Mexican land grant in present-day Lake County, California given in 1845 by Governor Pio Pico to George Rock. Rancho Guenoc was one of three land grants (along with Rancho Lupyomi and Rancho Collayomi) in Lake County. Lake County was formed in 1861 of land taken mainly from Napa County and the northwest portion taken from Mendocino County.

Rancho Guenoc encompassed essentially all of Coyote Valley including Guenoc, stretching from the range of low mountains just north of Middletown to what is now the southern end of Spruce Grove Road, and from the most westerly curve of Putah Creek eastward and dipping south to encompass what became the Guenoc winery and vineyards.

History

Rancho Guenoc was six square league land grant encompassing essentially all of Coyote Valley. George Rock (also known as George Roche and probably George La Roche) was born about 1785 in Canada and died after 1850. He lived at Guenoc from about 1848, as agent for Jacob P. Leese. In 1850 Rock built a log cabin in the area where the Stone House is now.

George Rock by deed dated 13 Jan 1847 and witnessed by Richard Fowler and Andrew Hoppener, sold Rancho Guenoc to Jacob P. Leese (1809-1892). Leese was a trader from Ohio who had married María Rosalia Vallejo, sister of General Vallejo, and was the owner of the adjacent Rancho Collayomi.

Editorial summary

Begin with the source’s own compact description: “Rancho Guenoc” is mexican land grant in California. The dossier treats that line as a proposition to test through Rancho, Guenoc and Mexican, not as a finished interpretation.

Editorial reviewA practical starting point whose main value is the path it opens into stronger specialist and primary sources. The current lead gives the account dated anchors—1845, 1861, 1785, 1850—that can be checked directly. The selected authority fields contribute no independent date. For this dossier, Rancho, Guenoc and Mexican is the immediate research focus.
Editorial analysis

Why this record matters

The phrase “mexican land grant in California” supplies a clear boundary for inquiry. It also exposes the unanswered questions: who defined that boundary, when it became stable and which sources sit outside it.

Evidence profile

Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Jul 20, 2026. The linked authority identifier is Q7290996. The first chronological checks are 1845, 1861, 1785 and 1850.

Critical limits

Overview language is designed for orientation and should not be treated as a substitute for the evidence cited beneath it. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.

How to read it

Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.

Best used for
  • Subject orientation
  • Search vocabulary
  • Locating named sources
Verify next

The closest primary source, responsible institution and strongest cited specialist reference.

Three-step research path

  1. Establish the record: confirm the title “Rancho Guenoc”, its source revision and the description used here.
  2. Expand the search: follow Rancho Guenoc primary sources, Rancho Guenoc archive and Rancho research across catalogues and specialist indexes.
  3. Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.

Questions for further research

  1. Which source most directly establishes the central claim about “Rancho Guenoc”?
  2. Which institution is responsible for the underlying evidence?
  3. Which cited source is closest to the event, object or claim?
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Source & attribution

This entry incorporates text from “Rancho Guenoc” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.