Preserved arrastra (not a mock-up!) off the trail to Winnemucca Lake, near Carson Pass, California. This was an early ore-crushing device. A pole in the center of the circular patio acted as a vertical axle. It supported one or more crosspieces to which heavy stones were attached by chains. Draft animals hitched to the crosspieces would rotate them around the axle, dragging the stones across the patio on which the ore had been spread. The name comes from Spanish arrastrar, to drag, and the device was introduced by early Mexican miners. Altho crude, an arrastra could be made quickly from local materials, aside from the chains, and so was very practical for the conditions. The insets show an interpretive sign and a close-up of the center stone where the axle was attached. Map location is approximate.