Elkhorn is a census-designated place (CDP) in Monterey County, California, United States. Elkhorn was a stop on the Southern Pacific Railroad 13 miles (21 km) northwest of Prunedale, at an elevation of 10 feet (3 m). The population of Elkhorn was 1,565 at the 2010 census, down from 1,591 at the 2000 census. Elkhorn was named after the elk in the area that have since gone extinct. Because Elkhorn is not incorporated, not all residents call the place they live Elkhorn. Some residents refer to Elkhorn as Castroville, Prunedale, Watsonville, or Salinas on mailed documents because Elkhorn shares ZIP codes with them. Other residents refer to Elkhorn as north Monterey County of which Elkhorn is a part.