Greenfield (formerly, Clarke Colony) is a city in Monterey County, California, United States[6] in the Salinas Valley, 33 miles (53 km) southeast of Salinas,[9] at an elevation of 289 feet (88 m).[6] The city was the fastest growing in the county during the 2000s, the population was 12,583 in 2000,[10] increasing to 16,330 in the 2010 census. Its most well-known public event is the annual Harvest Festival. Greenfield is a member of the Association of Monterey Bay Area Governments.