Shenandoah--Dives Mill National Register of Historic Places Listing

They built it in 1929. Just days before the stock market crashed, actually. The Shenandoah-Dives Mill near Silverton didn't care about Wall Street's panic. Instead, Charles Chase and his crew constructed this massive, multi-tiered flotation mill right on the steep mountain slope. It processed 15,000 tons of ore monthly. That is a lot of rock. Miners dragged gold, silver, lead, and zinc out of the Mayflower Mine and sent it screaming down an aerial tramway. The cable stretched 10,000 feet. Inside, giant steel ball mills crushed the ore into powder. Then, pine oil and chemicals bubbled the heavy metals to the surface. Flotation tech saved Silverton. While other Colorado towns starved during the Great Depression, this operation kept hundreds of local miners employed.

Most old mills got scrapped. During World War II, the government wanted iron, so they tore down old structures for the war effort, but the Shenandoah-Dives survived because it was still producing critical base metals. Today, it stands as a freakishly complete time capsule. Step inside. You can still smell the grease and ozone. The wooden stairs still creak underfoot. You can see the actual flotation cells, the thick canvas filters, and the control panels exactly where workers left them. It is one of the only intact pre-WWII flotation mills left in North America. Actually, it is a miracle it didn't burn down, considering how much dry timber makes up its skeleton.