On Thursday afternoon, Paula Fabel, Park City Mountain Resort’s communications director, leads a group of coworkers on a journey into Park City’s mining underworld. Among the others joining Fabel is Mary Flynn Ware, the resort’s Kids Mountain School director, Matt Ware, the resort’s food and beverage director, and Ian Patrick, a mountain host. Craig McCarthy, communications manager for the Park City Chamber/Bureau is also braving the trip. They don old hardhats with head lights, some of which have stickers that read “Keep Safety in Mine-D in ’79.” Across their waists, they wear belts with hefty battery packs that power the lights.

Looking to the opening of the Keetley Drain Tunnel, not much more than four feet wide, there is little more than a dot of light breaking through from miles away through the darkness. Soon, however, they will visit the No. 6 shaft, where, if they were to decide to ascend upwards to the surface about 1,500 feet, they would come up right next to the Stein Eriksen Lodge. Alternatively, if they were to decide to keep moving past the shaft, they would go through to the Ontario Mine.

At the surface, he remaining evidence of the gritty world below the pristine snow-capped mountaintops is a handful of old mine buildings with busted windows. It’s easy to forget, and hard to imagine, that Park City Mountain Resort and Deer Valley Resort sit atop a web of 300 miles of mining tunnel, part of 1,200 miles total beneath Park City the distance from the town to Chicago.

In commemoration of its 45th anniversary, this year Park City Mountain Resort gives free historical ski tours daily at 11 a.m., requiring mountain hosts to explain the decades of mining reaching back into the mid-1800s. To help give staffers a better idea of what Park City’s past looks like, hosts and other mountain personnel have taken tours from Keetley, near Jordanelle Reservoir, an experience that is not available to the general public. The Thursday crew of resort staff members is the second to take the trip.

“We want to know what’s happening below ground, not just above,” Fabel explains.

The group is in the capable hands of Lloyd Popp and Chad Wall, two of nine workers who maintain the Keetley Drain Tunnel daily, no longer for silver or any other precious metal, but for the Jordanelle Special Services District so that the river of water that moves at 11 cubic feet per second, just inches below the mine train tracks, continues to rush freely, half into the treatment plant for culinary water in Park City and half into the Jordanelle Reservoir.

Popp and Wall tell their guests they will be traveling at 15 miles per hour and to keep their limbs and jacket hoods inside the red metal carts because “there’s only about three-fourths of an inch clearance.”

Popp notes the tradition of scribbling names on the walls of mines and says some inside the tunnel written in black residue from the carbide lamps that miners used to use in the 1920s and 30s. “It’s a tradition,” he says. And, in fact, Popp’s name is on a wall near the Keetley portal dated 2004, next to Rick Martinez, son of Rich Martinez, Park City’s best-known “‘Ol Miner.” Popp has known the Martinez family some 30 years, when the Keetley tunnel served to drain water from the mines so silver could be extracted. He first came to the tunnel with his dad in the late 1940s, he says, then later began working at the mine in 1977. Not long after, hundreds of workers were laid off when the mine closed in the early 1980s. Today, Popp says he is one of only two former miners left at Keetley.

Though the Keetley tunnel’s history is old news to Popp, who knows the nooks and crannies like the back of his hand, he’s got a captive and excitable audience Thursday.

Ian Patrick, a mountain host who attended an earlier tour of Keetlexplained, “I’ve done hikes with Hal Compton from the museum and read books, but when you go into the tunnel, you’ll quickly grasp what it’s all about At the turn of the century, there were tons of mine buildings and thousands of people here working for the mines, and they’re all gone now I just find it fascinating.”