About This Place
Grass Valley (originally Centreville) is a city in Nevada County, California, United States. The population was 12,860 at the 2010 census, up from 10,922 at the 2000 census.
Grass Valley is located at 39°13′9″N 121°3′30″W / 39.21917°N 121.05833°W / 39.21917; -121.05833 (39.219215, -121.058414).
According to the United States Census Bureau, the city has a total area of 4.7 square miles (12.3 km²), all of it land.