Free Park City Museum presentation digs into historic mining methods in the Park City District
Mining Methods in the Park City District by Mark Danninger 5 p.m. on Thursday, March 21 Park City Museum Education and Collections Center, 2079 Sidewinder Drive Free parkcityhistory.org
Between the mid-1870s and the late 1970s, miners hauled out millions of pounds of silver ore from mines located around Park City.
Over a century, the mining shifted from individual prospectors to large-scale excavating.
Mark Danninger, mining engineer and project manager at the Rio Tinto Kennecott Copper Mine in Magna, will talk about that transition in a free presentation about the area’s mining methods at 5 p.m. on Thursday, March 21, at the Park City Education and Collections Center, 2079 Sidewinder Drive.
Danninger, who will use photographs and commentary to tell the story, will divide the century into three parts — the early days, the industrialization of the district and the later years.
“The early days encompass a 10- to 15-year period where there were a lot of small-time prospecting by mom-and-po
p ventures that were instrumental in identifying the ore bodies and their locations,” he said. “They would follow a vein of ore, load up their wheelbarrow or an ore cart and transfer the ore into burlap sacks and transport it to a smelter.”
The industrialization of the district began in the 1890s when these small ventures ran into issues that they could not afford to resolve, like flooding, Danninger said.
“They would begin a shaft and dig a couple hundred feet before the water inflow became too much for them to continue mining,” Danninger said.
Dewatering the mines required technological advances made possible by investors.
“These investors put money into the development of pumping technology, and steam and electricity played a pivotal role in dewatering,” Danninger said. “Drainage tunnels were also dug to get the water away from the shafts through the 1930s.”
Ventilation of the mines was another concern.
Miners in the early years relied totally on natural ventilation, and they could only dig so far until the air stopped circulating, Danninger said.
Some of these mines descended 1,200 to 1,500 feet deep, and from the 1930s up to the 1970s, the Ontario Mine went down to 2,100 feet, according to Danninger.
“Some small-time operators tried to put in some air shafts to help with the air flow, but those were very limited,” he said. “Steam and electricity, which helped with dewatering, were also used to power ventilation fans.”
The primary method of mining during this time was called sublevel or open stoping, Danninger said.
“That’s when you basically follow a narrow vein of ore, and sometimes that vein would horsetail, or break off into multiple veins,” he said. “The miners would then have to open up a huge room to get the ore.”
The bigger the room got, the bigger the danger of a cave in, according to Danninger.
To help prevent a cave-in, miners would use wedge wooden logs between the ceiling and floor to provide some support, he said.
“That had its own limitations, so as the room got bigger, they started using square-set timbering,” Danninger said.
Square-set timbering supports the walls and ceilings of a room with a system of interlocking wooden frames, Danninger said.
“The square-set timbering found its way to Park City some 20 years after it was developed in Nevada,” he said. Other technological advances that were introduced during the industrialization period included heavy machinery and the coming of railroad that would help transport the ore to smelters for refining, Danninger said.
“In the early 1900s, many of the mining companies began to merge, and we went from 30 different mines to half of that in terms of ownership,” he said.
A little more than 30 years later, during World War II, Park City’s mining industry began to slow down, and by the 1970s, the Ontario was the only working mine in town, Danninger said.
“Most of the mine owners and investors in the industry were optimists, and they would do whatever they could to keep a place intact to where it could start up again,” Danninger said. “But after a decade or two with no sign of restart, the mines were fully abandoned.”
Danninger, who has worked at Rio Tinto Kennecott for 12 years, developed his love of mining when he was a child, growing up in a mining district near Boulder, Colorado.
“There were a lot of ghost towns near my home, and we played in some of these old mine buildings when we were kids,” he said. “I got interested in the historic aspects of mining, and didn’t realize until I was in high school that I could get a degree in mining engineering.”
Danninger’s parents, however, wanted him to become a different kind of engineer.
“They would tell me I would never get a job with rocks, and when they told me I should become an engineer, they were thinking electrical engineer or something like that,” he said. “When I told them I wanted to be a mining engineer, they went ‘Oh, great.’”
Danninger said he volunteered to give his lecture in an indirect way.
“My wife and I periodically attend the talks the Park City Museum puts on, and we went to one in December that was about metallurgical processing that the district used,” he said.
That talk was given by Donovan Symonds, another mining engineer.
Danninger approached him at the end of the presentation and let him know that it would be interesting to hear a presentation about mining methods used in Park City.
“I was hoping he would have said, ‘Sure, do you want to help me with that?’ And that’s not how the discussion ended,” Danninger said, laughing. “It actually morphed into me volunteering to do the talk.”
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