Regularly active until 1945, it houses still-functional equipment for the separation by flotation of metals from crushed ores.

The Mayflower Mill stands east of the town center of Silverton, on the north side of County Road 2 in Arrastra Gulch overlooking the Animas River.

The principal mill building is a multistory wood-frame structure covered with corrugated metal roofing, its setting in the hillside designed to facilitate the feed of materials by gravitation.

It remained in regular operation until 1945, and was largely shut down thereafter to a decrease in government demand for metals occasioned by the end of World War II.

It was operated sporadically until 1992 under a variety of owners, and was then taken over by the San Juan County Historical Society as a museum.