San Francisquito Creek, named for the small Franciscan hermitage that once stood near its banks, defined the rancho's geography. The 'rincon' -- corner or nook -- described a bend in the creek where the land formed a natural enclosure suitable for grazing. Jose Pena's cattle would have grazed in the open grasslands of the valley floor, watered by the creek and sheltered by the willows and oaks that lined its banks. The creek's seasonal floods enriched the soil, making the surrounding land productive for both grazing and agriculture.

San Francisquito Creek remains a significant geographic feature. It still serves as the boundary between Santa Clara and San Mateo counties, a jurisdictional line that dates to the rancho era. When you cross the creek from Palo Alto into Menlo Park, you cross a boundary that predates both cities. The creek's persistence as an administrative dividing line is one of the more remarkable continuities between Mexican California and the present.

Pena's 8,418 acres occupied some of the flattest, most developable land in the Bay Area. That terrain, so useful for cattle ranching in 1841, proved equally useful for the suburban and commercial development that arrived a century later. Mountain View's streets, Google's campus, and the dense tech-industry infrastructure of the North Bay all rest on land that was once a single rancho, managed by one man who received it as a reward for political loyalty to a government that would be overthrown within a decade.