which county is pleasanton ca in
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.