Explore the Argo Mill and Tunnel Historic Gold Mill Tours

Follow the gold ore on its journey from the Argo Tunnel through the Mill. Along the way you'll learn about the people, technology, and the business that made this operation one of the most innovative and successful of its time. The Argo Mill is one of the largest and best-preserved Historic Gold Mills in the world, with much of its original equipment still in place.

The ambitious solution was an adit tunnel dug 4.16 miles into the mountain, tapping mine after mine along the way, draining nearly 300 miles of mine workings.

It took the better part of two decades to complete one of the longest tunnels of its kind in the world at the time. When finished, it served more than a hundred mines, keeping them viable for decades to come. In addition to draining the mines of ground water, the tunnel served many uses, allowing Ore, Equipment, Workers, Electricity, Compressed Air, Ventilation to reach deep into the heart of the Central City mines.

Completed in 1913, The Argo mill was built at the tunnel mouth to process the lower grade ore on-site before being loaded onto the Colorado and Central Railroad bound for the Denver Mint. The mill was one of the most technologically advanced operations of the time, harnessing Tesla and Westinghouse's alternating current long before Denver became electrified.

In 1943, a large group of mine workings collapsed into the argo tunnel, causing a catastrophic flood that closed milling operations for good. In 1977, the mill was purchased by James Maxwell who preserved it as a historic tour operation until its purchase in 2016 by the current owners. The Argo Mill and Tunnel is on the national registry of historic landmarks.