Rancho Posolmi was a 1,696-acre (6.86 km2) Mexican land grant in present-day Santa Clara County, California given in 1844 by Governor Manuel Micheltorena to Lupe Yñigo. The name refers to Posolmi village of the Ohlone. The grant encompassed present-day Moffett Field in Sunnyvale.
History
Lupe Yñigo (1781-1864), an Ohlone Indian, who was appointed an alcalde at Mission Santa Clara, was given a land grant in 1844, and retained over 800 acres (3 km2) until his death in 1864.
Robert Walkinshaw was a native of Scotland, who came from Mexico in 1847 to take charge of the New Almaden Quicksilver Mine for Baron, Forbes and Company, a British trading firm.
With the cession of California to the United States following the Mexican-American War, the 1848 Treaty of Guadalupe Hidalgo provided that the land grants would be honored. As required by the Land Act of 1851, a claim for Rancho Posolmi was filed with the Public Land Commission in 1852, and the grant was patented to Thomas Campbell, Robert Walkinshaw, and Lopez Yñigo in 1881.
In 1931, 1,000 acres (4.0 km2) were purchased by Bay Area communities and sold to the military for $1, to be used for an air base, later named Moffett Field.