Rail Road Flat is a Gold Rush era mining town that was settled by gold seekers in 1849, named for a wooden track which conveyed ore cars with waste rock to and from the diggings. A post office was established in 1857, and the first stamp mill erected in 1866. By 1872, five or six mills were operating, and at the turn of the century two stamp mills and one arrastra were still in operation.

The Clark Ditch was constructed to supply the placer mines of Rail Road Flat in 1856 and soon extended to the mines of Glencoe and Rich Gulch. Originating near Blue Mountain, it carried water from the South Fork of the Mokelumne over 55 miles, servicing two reservoirs and numerous downstream communities. Part of the Clark Ditch was purchased by the Calaveras Public Utilities District in the 1930s and water was converted from open ditch to pipe by 1976.

By Judith Marvin, 2002