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Firing up the Carissa mine
Already a popular spot for school field trips, the Carissa mill site at South Pass City is adding a new public feature --fully functional milling equipment. South Pass City State Historic Site

Firing up the Carissa

Jun 20, 2012 - By Robert H. Peck, Staff Writer

The Carissa is going to start rumbling again.

Beginning this summer, the Carissa mine and mill near the South Pass City State Historic Site will undergo some of its biggest renovations to date as it moves closer to a complete -- and spectacular -- public opening.

Although it has taken years to ensure the safety and historical accuracy of the mine's public opening, South Pass City curator of public programs Jon Lane said the project now is ready to move forward with the replacement of several pieces of missing mill equipment at the site, all of which will be installed before the site closes in the fall.

And the equipment won't just be sitting there. It's going to be fired up and operated as well.

Lane said the Wyoming Office of State Parks, Historic Sites and Trails has used funds appropriated by the Wyoming Legislature and Gov. Matt Mead to renovate the existing equipment so that it can once again be started and run, just as it was in the Carissa's final heyday in the 1940s.

"With essentially the flip of a switch, the processes will illustrate themselves for the public," Lane said. "We'll be able to replicate that milling process of 1946 as it originally was."

Finding the missing machines

In the past, Lane said, historians and renovators had only limited access to the Carissa site. The Abandoned Mine Lands Division of the Wyoming Department of Environmental Quality has an ongoing partnership with the Carissa restoration project, and it must ensure that all portions of the mine and facilities are safely accessible before they are given over to complete renovation, he said.

But beginning about two years ago, Lane said, the State Parks office began to use funding granted by the legislature to track down, purchase and move four pieces of milling equipment that had been missing from the mine site. He said the missing pieces were identified through photos taken in 1953 by the Library of Congress's Historical American Buildings Survey, which show the Carissa as it was around the time it ceased production shortly after World War II. When these photos are compared to the facilities as they are now, the missing equipment stands out, Lane said.

After determining what needed to be found, the State Parks office purchased four pieces from three different locations, Lane said.

Two of the pieces came from a dealer in Tucson, Ariz., where they had come to rest after being moved there from Twentynine Palms, Calif., and Pioche, Nev. From this dealer, the state purchased a rare Colorado Iron Works ball mill, which uses steel balls and water to crush gold ore, and an antique spiral classifier, a large tank with an auger suspended in its center used to help separate gold from other materials.

A third piece, this one a Denver Duplex mineral jig, was obtained in Salt Late City. Mineral jigs, a part of the sluicing process, helped to further refine the refuse that entered the mill from the mines.

The final acquisition was a little closer to home. Lane said another mill was transported back to the Carissa from a separate Wyoming facility near Atlantic City, where it had been moved following the Carissa's closure decades earlier.

None of the four pieces had been manufactured for at least 40 years, Lane said, meaning that antique industrial equipment is a niche market for most dealers.

The rarity of 1940s milling equipment also made the next part of the renovation challenging. Lane said the historians behind the project didn't just want the Carissa's machinery to look authentic. They wanted it to work.

Restoring the mill

Though it has been more than six decades since most of the Carissa's ancient mill machines were operated, Lane said they are still in very good condition.

"If they were trying to win the war, the manufacturers should have put less copper in these things and just made more of them," he said. "They were certainly not considered disposable. They were built to last."

Lane said the sturdy craftsmanship that went into the mine's equipment means that most of it is still structurally sound and will require only a good cleaning and the replacement of non-metal parts, such as belts and tubing, to run again.

The exceptions were the massive electric motors that provided power to the entire operation. Build by General Electric in 1946, the motors certainly were reparable, but they would need more of a professional touch if they were going to work.

To that end, Lane said the old motors were sent to Integrated Power Services in Rock Springs for repairs. IPS not only repaired them, he said, but renovated them so they will run just as they did in their time, meaning that the entire milling operation will look -- and sound -- practically the same.

Lane added that IPS was highly enthusiastic about the project.

"They were fantastic," he said. "For them it's like someone bringing in a 1950 Cadallic. They all had their photos taken with it."

Mine challenges

Finding and renovating the equipment at the Carissa mill has been a major step forward for the above-ground portions of the facility's public opening, but one portion of the site remains inaccessible: the five-level underground shaft complex that the miners would delve into to extract gold before it was sent on to the mill. While the elevator building at the top of the shaft has already been opened to the public, Lane said the underground remains completely flooded, and likely will stay that way for some time.

Mining at any location eventually will produce some flooding, Lane said. This is due to the natural watershed that lurks beneath the land. At South Pass, the shed is 60-80 feet below the surface.

Lane said this water was the eventual cause of the Carissa's deterioration, because miners were ill equipped to extract minerals while simultaneously bailing water out of the shaft. Nowadays, the water is inhibiting the full reopening of the Carissa mine, just as it hindered the mine's original occupants half a century ago.

Lane said the Carissa hasn't been completely pumped out since the 1990s, when a Canadian firm evacuated the water all the way down to the fourth of the mine's five levels. The firm did so to allow geologists and divers to access the shaft, a project that ultimately fell through before the State of Wyoming reacquired the mine.

In the dry season, the mine would only need to have around 1,300 gallons of water a day removed in order to remain dry, with the figure jumping to 3,500 gallon in the wet season as mountainous snowcaps began to melt.

Lane said these numbers would be manageable even for a small household pump, were the flooding on the surface. But at a depth of 400 feet, a bigger machine is needed. That machine is unlikely to be installed any time soon, though. Lane said acquiring a permit to dispose of the water, and ensuring that underground renovations could be conducted safely, are likely to take years. For now, the operational mill above ground will have to sate the public demand.

Safety first

Lane said a standing memorandum of understanding with the AML division has ensured that safety is at the forefront of the Carissa renovation project so far. While the State Parks office and historians such as Lane focus on the accuracy and authenticity of the area, the AML side of the project makes sure the public will be able to access the equipment without danger. Lane said AML has been working to incorporate new stairways, guardrails, handrails and modern lighting into the Carissa mill buildings, ensuring that, when the machines are ready to roll by this time next year, observers won't be left in the dark.

"The AML is very good about reminding us that this is not, in fact, the 1940s," Lane said. "State Parks can't tip their hats enough to the folks of AML. We're lowly historians here, but they bring scientific expertise to the project."

He added, "But we bring the story."

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