Peirce Mill is a water-operated grist mill located in Rock Creek Park, Washington, D.C. It was built on 1820s by Isaac Peirce, together with a house and other buildings and was acquired by the federal government in 1892 as part of Rock Creek Park. Considered to be the sole survivor of at least eight mills along Rock Creek, Peirce Mill was used to grind corn, wheat and other grains. During its inception, the mill was an ancestor of several industrial innovations which decreases manual labor. These devices include grain elevators, hopper boy and screw augurs, which are all driven by a vertical shaft connected to a water wheel. When its main shaft broke down, the mill ceased its commercial operations in 1897.

Additionally, during the 1930s, the mill was restored and was again operational. Since then it was opened for public viewing, it even supplied government canteens with flours processed in mill until the 1940s. However, in 1993, the mill was shut down due to deterioration and damage on its major parts. Despite its changes over the course of history, visitors can still experience the original atmosphere of the grist mill. Most of the mill?s exterior and interior parts have retain the original appearance, together with its 170 year-old stone walls, wooden milling machinery and oak floor boards. The interior of the mill is like a gigantic cuckoo clock, visitors will be astounded by enormous wooden gears, pulleys, shafts and conveyers. On the adjacent side, visitors will be amazed by the three colossal sets of millstones, mostly weighing 4,000 pounds and are made of quartz.

Today, the mill is still on its restoration phase, until then, the mill will be closed to public exhibitions. But guests and visitors can still visit the Peirce Barn which is just adjacent to the mill. The barn serves as the information center about the Peirce family, their estate and other mills inside the Rock Creek Valley.