Entry No. 46 — the Salt Lake City file — filed under: historic
Ontario Mine
Discovered in 1872 and later purchased by mining magnate George Hearst, the Ontario Mine was once one of the world's most productive silver mines, yielding over $50 million in wealth. Today, the defunct site features the preserved 80-foot-tall Ontario No. 3 steel headframe, a historic shaft house, and several wooden water tanks. While the underground workings and a former 1990s tourist mine ride are permanently sealed, these towering surface structures remain standing as silent monuments to Park City's boomtown era.
The story
When silver was struck here in 1872, mining magnate George Hearst stepped in to buy the Ontario Mine, turning it into a juggernaut that eventually bled out over $50 million in wealth and laid the groundwork for the Hearst empire. But extracting that fortune was a constant war against underground flooding. By 1882, mine manager R. C. Chambers had to bring in engineer David Keith specifically to install a giant Cornish pump just to keep the lower shafts from drowning in water.
The mine kept shifting hands through the 20th century—including a 1970s stint under Park City Ventures, a joint venture between Anaconda and ASARCO—before a $3 million investment in the 1990s briefly converted the deep shafts into a underground tourist train. That tour proved short-lived and was welded permanently shut. Developers still eye the surrounding bench for housing projects, but the actual mine core remains frozen in time.
What it's like
You won't be riding any train deep into the earth—the underground workings were permanently sealed decades ago. Instead, pull off Marsac Avenue at the Ontario Mine Trailhead. Right past the perimeter fence, the 80-foot steel tower of the Ontario No. 3 headframe looms over a scattered collection of original wooden water tanks and the old shaft house. Hike or snowshoe up the Ontario Bypass trail for elevated line-of-sight photos, but don't try hopping the chain link: the ruins are private property, clearly signed, and watched closely.
The move: Park at the Ontario Mine Trailhead off Marsac Avenue and take a scenic hike or snowshoe excursion along the Ontario Bypass trail, enjoying panoramic mountain views and photographing the historic headframe and water tanks from a safe distance.
📍 Before you go The historic mine structures and sealed shaft are located on private property and fenced off for safety, but they can be easily viewed and photographed from the public Ontario Mine Trailhead and Marsac Avenue.
- 📍 Park City
- 💸 Free
- ⚡ Low-key
- 🌗 Outdoors
Where: Park City, UT 84060, USA
Hours: Added 2026-07-20 — confirm current access before you go.
Pair it with
- Judge Mine Tunnel — Drive less than half a mile down the drainages to spot another remnant of Park City's flooded underground past.
- Silver King Mill — Head under a mile away to see the massive ore-processing facility that rivaled Ontario's surface footprint.
- Silver King Mine — Compare Hearst's steel headframe with the slopeside complex of Park City's other dominant silver producer.
Good to know
Can you go inside the Ontario Mine or down the shaft?
No. The underground tunnels and the short-lived 1990s tourist ride are permanently sealed with concrete and steel, and the surface structures are fenced on private land.
Where is the best spot to view and photograph the ruins?
Park at the Ontario Mine Trailhead on Marsac Avenue or walk along the Ontario Bypass trail for high vantage points of the headframe and water tanks.
Who was George Hearst and what was his connection here?
George Hearst was a wealthy 19th-century mining magnate who purchased the Ontario Mine shortly after its 1872 discovery, using its massive silver output to build his family's fortune.
What are the giant wooden cylinders on the site?
Those are historic wooden water tanks used during the mine's operational peak to supply water for ore processing and surface operations.
Plan a visit & invite your people →
Further reading: townlift.com · allseasonsresortlodging.com · parkcityhistory.org · archive.sltrib.com · Reddit
last checked: 2026-07-20