Built in 1929 by the Shenandoah Dives Mining Company, the Mayflower Mill processed ore from the Mayflower Mine and other Silverton-area mines, using the flotation process to extract gold, silver, copper, lead, and zinc. During the war years, more than 40 small mines shipped ore there, and except for a few years in the 1950s it operated continuously for nearly 60 years. More than 10 million tons of ore yielding more than 1.5 million ounces of gold and 30 million ounces of silver were processed, and when it closed in 1991 it was the second oldest operating gold mill in the United States. Ore from the Mayflower Mine in Arrastra Gulch traveled nearly two miles to the mill on an aerial tram, whose heavily loaded buckets ran downhill by gravity while empty buckets were pulled back up with little power, and miners often rode the buckets to work. Later, ore from the Sunnyside Mine was trucked to the mill. In 1957, the mill served as the set for the western film "Night Passage," starring James Stewart and Audie Murphy, including a gunfight scene and a tram-bucket escape. It is now owned by the San Juan County Historical Society, which offers daily summer tours.