Walnut Creek is a city in Contra Costa County, California, United States, located in the East Bay region of the San Francisco Bay Area, about 16 miles (26 kilometres) east of the city of Oakland. With a total estimated population of 67,673, Walnut Creek serves as a hub for its neighboring cities because of its location at the junction of (I-680) and San Francisco/Oakland (SR-24) and its accessibility by BART. Its active downtown neighborhood features hundred-year-old buildings and extensive high-end retail establishments, restaurants and entertainment venues.

There are three bands of Bay Miwok Indians associated with early Walnut Creek: the Saclan, whose territory extended through the hills east of present-day Oakland, Rossmoor, Lafayette, Moraga and Walnut Creek; the Volvon (also spelled Bolbon, Wolwon and Zuicun) near Mt. Diablo; and the Tactan located on the San Ramon Creek in Danville and Walnut Creek.

Today's Walnut Creek is located within the earlier site of four Mexican land grants. One of these land grants – measuring 18,000 acres (73 km²) – belonged to Juana Sanchez de Pacheco, who eventually passed the land down to her two grandsons. Ygnacio Sibrian, one of the grandsons, created the first roofed home in the valley in about 1850. The grant was called Rancho Arroyo de Las Nueces y Bolbones, named after the principal waterway, Arroyo de las Nueces (Walnut Creek), as well as for the local group of indigenous Americans (Bolbones). The Arroyo de las Nueces was named for the evidence of the native species of walnut tree, the California Walnut.

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