Only four of the 16 original kilns survive today, now protected and interpreted by the US Forest Service and listed on the National Register of Historic Places.
The kilns are dwarfed by the towering mountains on both sides of the valley. They seem small at first, but as you approach them their scale becomes more apparent. They are 20 feet high—about the height of a two-story house—and 21-and-half feet in diameter. The circumference around the 14-inch-thick walls is about 73 feet.
Warren King of Butte, Montana, constructed the kilns in 1885 to service the needs of the Viola mine smelter across the valley in Nicholia. The kilns operated from 1885 to 1889. It was not a small operation. Some 200 men—mostly Irish, Italian, and Chinese immigrants—worked the nearby forests cutting, sawing, and transporting four-foot lengths of log, then carefully arranging them inside each kiln, stacked on end. The two-day burn reduced about 35 cords of wood to 500 pounds of charcoal.
Following a fire at the hoisting works, the Viola mine closed in 1889. The price of lead and silver kept it closed.
Locals discovered the utility of the perfectly good bricks and made most of the kilns into buildings and walls around the valley.