Pleasanton is a city in Alameda County, California, incorporated in 1894. It is a suburb in the San Francisco Bay Area located about 25 miles (40 km) east of Oakland, and 6 miles (9.7 km) west of Livermore. The population was 70,285 at the 2010 census. In 2005 and 2007, Pleasanton was ranked the wealthiest middle-sized city in the United States by the Census Bureau. Pleasanton is home to the headquarters of Safeway Inc. and Polycom. Although Oakland is the Alameda County seat, a few county offices and a courthouse are located in Pleasanton. Additionally, the main county jail is in the neighboring city of Dublin. The Alameda County Fairgrounds are located in Pleasanton, and the annual County Fair is held there during the last week of June and the first week of July. Shadow Cliffs Regional Park is located on the east side of town.
Pleasanton is number 63 in CNNMoney.com′s list of "The Best Places to Live" in 2010, and was also named one of "Americans' Top Hometown Spots" in the United States in 2009 by Forbes.
Pleasanton is located on the Rancho Valle de San José Mexican land grant and was founded by John W. Kottinger, an Alameda County justice of the peace, and named after his friend, Union army cavalry Major General Alfred Pleasonton. A typographical error by a U.S. Postal Service employee apparently led to the current spelling. One of the earliest houses built in the valley in 1854 is still standing and serves as the centerpiece of the Alviso Adobe Community Park. In the 1850s, the town was nicknamed "The Most Desperate Town in the West" and it was ruled by bandits and desperados. Main Street shootouts were not uncommon. Banditos such as Joaquin Murrieta, upon whom the legend of Zorro is based, would ambush prospectors on their way back from the gold rush fields and then seek refuge in Pleasanton. This reputation passed and in 1917, Pleasanton became the backdrop for the film Rebecca of Sunnybrook Farm, which starred Mary Pickford. The town was once home to Phoebe Apperson Hearst, who lived in a 50-room mansion on a 2,000 acre (8 km²) estate, now the site of Castlewood Country Club.