Patented as a townsite in 1872, this early town derived its name from a sawmill located here. A post office established at Mountain Ranch in 1856 was moved to El Dorado in 1868, and El Dorado thus became known as Mountain Ranch. A bell was used from 1885 to 1953 in the local school, which had been established as Cave City School District in 1855. In 1946, this school joined with the Banner District to become the El Dorado Union Elementary School District.