Between 1872 and 1982 the Park City mining operations were home to 34 operating mining shafts varying from 275 to over 2,400 feet deep. The sides of the shafts were supported with timber frames and wood planks. These wood supports required frequent maintenance because of wet conditions underground and, once these mines closed, the wood supports rotted, leading to collapse of the shaft walls, especially in the upper soil and gravel zones.
That’s what happened in May 2015 when the upper part of the Daly West shaft collapsed, toppling the steel headframe that had stood over the shaft for 100 years. The shaft was immediately plugged but the mangled steel headframe lay on its side with an uncertain future. Then the Friends of Ski Mountain Mining History (FOSMMH), a committee of the Park City Museum, helped encourage a collaboration of Empire Pass Master Owners Association, Deer Valley Resort, and Park City Municipal to repair the headframe and raise it on a site near the shaft in 2022 as a monument to Park City’s mining legacy.
The FOSMMH started in 2015 to assist the City and Park City Mountain Resort in saving the historic mining structures within the resort. Since then, they have supported the stabilization of multiple mining structures. Each of these projects involved coordination with the City so the finished projects are historically correct. We added signage at many sites (including locations where there is no longer a structure) to educate those who pass by on the history of the old mining structures and their contribution to the industry that once thrived in Park City. All of this work is paid for with local grants, city and resort contributions, private donations, and in-kind corporate support.
Now the FOSMMH are tackling their biggest projects yet, closing the shafts and stabilizing the headframes and mine buildings at the Silver King Coalition Mine site across from the resort’s Bonanza lift, and the Thaynes Mine just uphill from the Thaynes lift. Both sites have historic steel headframes and other mining equipment still in place.
In the case of the Silver King site, the 1880s-vintage shaft was backfilled with earth in the 1990s, but the backfill settled – leaving a crater at the top of the shaft that threatened the foundations for the headframe. The FOSMMH hired an engineering firm to prepare designs to fill the crater and cap the shaft with concrete to stabilize the foundations of the headframe. The Utah Division of Oil, Gas & Mining used their funds, and the designs provided by the FOSMMH, to hire a contractor to construct the shaft plug and cap in 2023. They are now repairing the rest of the Silver King mine building in a multi-year project, which is expected to cost over $1.6 million.
Credit: Photo by Dalton Gackle, courtesy of the Park City Museum
The FOSMMH are also working on stabilizing the Thaynes mine shaft and headframe in upper Thaynes Canyon. That shaft is collapsing and forming an unstable cavern in the subsurface, with visible settling of the ground at the surface around the shaft and structural damage to the 1936 steel headframe. In a race against time and mother nature, the FOSMMH have an engineering firm designing a plug for the shaft to arrest the collapse.
The State of Utah is ready to contract for the necessary work in the shaft. However, the above average snowfall at the site over the last two years, along with regular underground water flow, have caused challenging conditions. The entire roof of the mine building collapsed under the record snow in April 2023 and this hazard was only recently mitigated by the FOSMMH with City and resort funds. The increased water recharge from all the melting snow increased groundwater flow into the subsurface cavern, delaying the 2024 plans of the State to implement the designs provided by the FOSMMH, and possibly requiring a redesign for another construction attempt in 2025.
The Friends of Ski Mountain Mining History are undaunted by the challenges they face in stabilizing the remaining local historic mining structures for the long-term educational benefit of Park City residents and visitors. So, the work continues. You can help support this mission by making a tax-deductible donation.
The Park City Museum and Friends of Ski Mountain Mining History are hosting a free lecture titled “Ghosts of the Past: Unearthing Utah’s Mining History Through Abandoned Mines” given by mining expert Stuart Burgess on Wednesday, January 15 from 5-6 p.m. at the Museum’s Education and Collections Center located at 2079 Sidewinder Drive.