In Sutter Creek is the historic Knight's Foundry (sometimes called Knight Foundry).
Knight's Foundry is considered the only remaining water powered foundry and machine shop in the United States.

Founded in 1873 as Campbell, Hall and Company, the foundry was bought out by Samuel Knight, a ship's carpenter. Knight had labored in a number of mining camps and had dabbled in perfecting a more efficient metal water wheel.

Knight experimented along the lines of the Pelton Wheel. In fact, some sources indicate the Knight Water Wheel predated the Pelton Wheel, but the jury is still out on that. At any rate, the Knight Water Wheel and the Pelton Wheel were similar in design and in their positive impact on the development of Gold Country mining through providing a cheap and effective energy source.

By the 1890s, Knight had produced more than 300 wheels that were being used to power more than 2000 stamps in mining mills. However, the Pelton design was generally considered the most reliable.

In 1883, a contest between Lester Pelton and Samuel Knight resolved the issue. At the Idaho Mine in Grass Valley, both designs were tested - Pelton won, and became the industry leader in industrial water wheels.

Samuel Knight did not despair, however. He responded by producing a vastly improved electrical governor that controlled the speed and supply of water to the wheels, regardless of who manufactured them. Knight's Foundry prospered and became a prominent manufacturer of mining equipment, hydraulic buckets, dredger pumps, mining hoists, road working equipment, and lumber machinery. Knight's company held seven different patents for industrial machinery fabricated in the foundry.

Samuel Knight died in 1913, but the foundry continued. Through the early 1990s, Knight's Foundry supplied machine parts for mining, agricultural, and timbering firms.
When the California State Capitol was restored in the 1970s, Knight's Foundry provided reproduction architectural ironwork for the project.

Knight's Foundry is registered California Historical Landmark #1007, and it is listed in the National Register of Historic Places. In December 1995, the Foundry lost its lease and closed it doors. The Smithsonian Institution has labeled Knight's Foundry as one of the most endangered historic places in America. A Save Knight's Foundry Task Force is leading the efforts to preserve the complex.