Mountain Ranch (formerly, El Dorado and El Dorado Town) is a census-designated place (CDP) in Calaveras County, California, United States. The population was 1,557 at the 2000 census. The town is registered as California Historical Landmark #282. The town center is quite small with less than 50 people living in it, the 5 mile square area surround the town accounts for the balance of the population.