Knight Foundry in Sutter Creek, California, was established in 1873 as a cast-iron foundry and machine shop serving the Mother Lode’s mines and timber industry. It is significant as the last water-powered foundry and machine shop in the United States, still driven by a 42-inch Knight Wheel developed by Samuel N. Knight. His high-speed impulse water turbine became an important forerunner of the Pelton wheel and was widely used across the western United States. As mining declined, the shop survived by producing specialized machinery and patented equipment. Operating until 1996, it was later donated for preservation and remains open to the public as an important historic industrial site.