The Mishewal-Wappo had inhabited the Napa Valley for centuries, and the Caymus were among the groups who lived along Sonoma Creek and its tributaries. Spanish missionaries made their first incursions into the area in 1823, and Mexican governance brought the rancho system -- a mechanism for distributing vast tracts of indigenous land to settlers who would ostensibly develop and defend them. Yount's grant encompassed the heart of the valley: the land that would become Yountville, Oakville, and Rutherford. The name Caymus survived the transition from indigenous homeland to colonial property to American township, but the people it described did not fare as well. By the time Yount built his blockhouse in 1836 and erected an adobe home the following year, the Wappo population had already been devastated by missionization and disease. The rancho bore their name even as it displaced their presence.

Yount was no gentleman rancher. He built a Kentucky-style blockhouse -- a fortified log structure designed for frontier defense -- making him the first permanent Euro-American settler in the Napa Valley. The blockhouse still exists as a California State Historical Landmark. In 1843, Yount expanded his holdings northward, receiving the one-league Rancho La Jota on Howell Mountain. He raised cattle, grew crops, and worked the land with the practical skill of a man who had spent decades surviving on the American frontier. Born in 1794, Yount had already lived a full life as a hunter and craftsman before California became his final chapter. His grave, also a state landmark, notes that he received the first Mexican land grant in Napa Valley -- a distinction that would shape the region's identity long after the rancho system itself dissolved.

When the United States seized California after the Mexican-American War, the Treaty of Guadalupe Hidalgo in 1848 promised that Mexican land grants would be honored. The promise came with a bureaucratic catch: the Land Act of 1851 required every grantee to prove the validity of their claim before the Public Land Commission. Yount filed his claim in 1852, but the patent for Rancho Caymus was not issued until 1863 -- eleven years of legal uncertainty during which his ownership hung in the balance. Many rancheros lost their land to the cost of litigation alone, forced to sell parcels to pay lawyers. Yount survived the process, but the decade of legal limbo illustrated a larger pattern: the American government technically honored the grants while creating a system that systematically stripped their holders of the resources to keep them.

Yount died in 1865, two years after finally securing his patent. A town that had been laid out on his property in 1855 under the name Sebastopol was renamed Yountville in 1867 -- the town of Sebastopol in neighboring Sonoma County had already claimed the name. With no clear heir to manage the estate, the courts stepped in to sell the remaining portions. Judge Serranus Clinton Hastings -- the first Chief Justice of California and founder of Hastings College of the Law -- purchased a substantial section of the original rancho. Hastings later sold parcels to Captain Gustave Niebaum, the Finnish sea captain who would found Inglenook Winery, and to California State Senator Seneca Ewer. The fragmentation of Rancho Caymus into smaller properties planted the seeds of the Napa Valley wine industry. The land Yount had worked as a frontier homestead became, within a generation, the foundation of one of the world's premier wine regions -- the Napa Valley AVA that now occupies the same acreage the Caymus people once called home.