George Yount, an American frontiersman born in North Carolina in 1794, moved with his family to Missouri at age 10 and came to California in 1831. In 1836 he received a large tract of land in Napa Valley from the Mexican government, known as Rancho Caymus. About 1843 he built a flour mill on this land grant near the Napa River, one-half mile northeast of present-day Yountville, and it became the first mill in Napa Valley. The Star of the Pacific Mill used a waterwheel to drive two pairs of millstones and was capable of producing 30 barrels of flour, or 5880 pounds, a day. Yount used this surviving pair of millstones at the mill; made of fresh water quartz from a quarry in the Marne Valley outside Paris, France, they were considered the highest quality available and were sought by flour mills throughout the country. After Yount's death in 1865, Frederick Ellis, a miller from New York, continued operating the mill after purchasing it from Yount's estate in 1870, and the original account ledger shows that the mill was still in use in 1892.