The cylinder has many holes in it to allow undersized material (including gold) to fall into a sluice box. On large gold dredges, the buckets dump the material into a steel rotating cylinder (a specific type of trommel called 'the screen') that is sloped downward toward a rubber belt (the stacker) that carries away oversize material (rocks) and dumps the rocks behind the dredge. The material is then sorted/sifted using water.

Small suction machines are currently marketed as 'gold dredges' to individuals seeking gold: just offshore from the beach of Nome, Alaska, for instance.Ī large gold dredge uses a mechanical method to excavate material (sand, gravel, dirt, etc.) using steel 'buckets' on a circular, continuous 'bucketline' at the front end of the dredge. The original gold dredges were large, multi-story machines built in the first half of the 1900s. Gold Dredge, Klondike River, Canada, 1915 The Yankee Fork dredge near Bonanza City, Idaho, which operated into the 1950s.Ī gold dredge is a placer mining machine that extracts gold from sand, gravel, and dirt using water and mechanical methods. As the dredge worked, it continuously dug into its own pond in front and filled it in with tailings at the back.For the historic landmark in the United States, see Gold Dredge. After its completion, the pond was filled with the 8-10 feet of water needed to float and operate the 988 ton dredge. Sometimes it took a whole day to load just one truck with some of the pieces needed to build the dredge.Īnother trucking company delivered the twenty-five pontoons, each measuring 10x10x27 feet, by hauling them over Galena Summit, no small feat. One of the largest loads was the 55-foot, 17.5 ton spud. Some pieces were shipped by rail to Mackay and trucked there by Lindberg’s Trucking Company of Mackay to the Yankee Fork site over Spar Canyon Road.

It was a major operation to transport the equipment and pieces needed to build the dredge. Winch room at the Yankee Fork Dredge Construction of the Yankee Fork DredgeĪ pond for the Yankee Fork Gold Dredge was constructed to allow the assembly of the massive four-story floating machine.

Gold dredge idaho