Mining History: Stamp mill 'mind-numbingly deafening'

Mining History: Stamp mill 'mind-numbingly deafening'
Jon Lane, curator of public programs at South Pass City Historic Site, stands with an 1850s-era stamp mill in South Pass City on Feb. 22, 2013. A grant from the Wyoming Cultural Trust Fund is helping to fund the mill's relocation to its 1896 location in August. (Kyle Roerink, Star-Tribune)

SOUTH PASS CITY, Wyo. - A short hike from the main drag of restored Gold Rush-era buildings in South Pass City sits an idle, nine-ton piece of machinery called a stamp mill.

It has moved four times during its nearly 150 years of existence. It once toppled over while sitting on a hillside. Metal parts have at times been wrested from its wooden frame and sold. The outfit survived World War II scrap drives because someone had moved it out of sight behind a hill.

"It's special," said Jon Lane, curator of public programs at historic South Pass City. "Its remote location over here is why this one is the last one that's survived."

This summer, the deserted piece of gold mining technology will be transported in one piece to its 1896 location along a nearby creek. The mill will be one of nine stops along a new 1.6-mile trail slated to open in South Pass City in August.

"[Stamp mills] were the heartbeat, really, of the community up here," Lane said.

At the turn of the 20th century, the deafening thud of 850-pound arms pummeling rock echoed day and night in South Pass City. Gold rush hopefuls fed quartz-filled chunks of granite into the mill, which broke the rock into smaller pieces to get at nuggets of gold trapped inside.

The process was slightly improved Stone Age technology, Lane said. At best it was about 60 percent efficient, allowing nearly half the sought-after gold to wash away, still implanted in excess rock.

Along with the stamp mill, South Pass City's new trail will be dotted with a water wheel-powered grinding machine, a kiln used to make bricks for buildings that still stand today and informational signs telling the story of South Pass City's big boom and quick bust. The roughly $40,000 project is paid for with dollars from the Wyoming State Parks Historic Sites and Trails and a Wyoming Cultural Trust Fund grant.

"We saw this as an opportunity to expand their audience," cultural trust fund administrator Renee Bovee said of the new trail. "The person who wants to be outdoors enjoying the beauty of the area can also say, 'So that's what that piece of equipment does.'"

A stone's throw from the new trail site is Wyoming's oldest mining claim, a gold mine known as the Carissa Mine. This summer, its once-defunct mining equipment will roar to life for the first time since 1954.

Mining machinery resurrected

Starting in August, visitors to the Carissa Mine will not just tiptoe around dormant machinery as they have in years past. A new electrical system will power four massive mining machines -- including a ball mill to pulverize ore and a shaking table to separate gold from rock -- for visitors to see and hear.

The site's whole interpretive plan, and what visitors to South Pass City will start seeing late this summer, is demonstrable equipment, said the historical site's superintendent, Joe Ellis.

Lane, the site's curator, called the machinery that will again move and shake this summer "mind-numbingly deafening."

"You've never heard anything like it," he said.

Since 1999, nearly $4 million of Abandoned Mine Land funding has helped pay for structural stabilization and safety improvements at the Carissa Mine, Ellis said. An indoor observation deck scheduled to be built this summer will be AML's last touch on the mine site, according to AML project manager Marcia Murdock.

For visitors wanting a walk through Wyoming's mining history, historic South Pass City will be open for tours on weekends starting May 15. The adjacent Carissa Mine will be open for tours by mid-August and the new historic trail will open Sept. 1.

"It's the technology. It's the architecture. It's the working conditions," Lane said. "There's something here for everybody."