Originally known as El Dorado Camp, the town’s name was changed in 1868 when the post office was moved here from the original Mountain Ranch, which was located one mile away on Whiskey Slide Road.
Little is known of El Dorado Camp’s early history. It was apparently named after a local sawmill which must have been a busy operation, located in the midst of some fine stands of tall timber. The early day miners in the district suffered from a lack of water during the dry season, until a ditch was cut to supply water year-round. After its completion, the area enjoyed a small measure of success before the placers gave out. The town reached its peak during the 1870’s, as due to its location on the main road between the railhead at Valley Springs and the nearby mining camp of Sheepranch, it became the major trading center for the miners in the region.
Mountain Ranch is located nine miles from San Andreas via Mountain Ranch Road.
The Domenghini General Store is the oldest building in Mountain Ranch. Built in 1856 by a man named Pagani, this structure was built from stone, adobe and hand-hewn beams and has a full basement. The building material was dug from nearby Adobe Gulch which is located just south of town. The walls are twenty-four inches thick, and combined with the iron shutters, the building is practically fire-proof. Inside is a wooden plank floor with glass windows inlaid to provide light to the basement below. The Domenghini family purchased the building in 1872, using it as a saloon, pool hall and dance hall until 1901.
The Dughi Building was built in the late 1860s by the Raggio and Dughi families. Bertolameo Dughi operated a general store here for many years and also served as postmaster in 1868. The building has served a number of purposes over the years and is quite a well-known landmark in the area.