Holly Bidle stands inside the mine accessible from her home's laundry room. (Courtesy of Holly Bidle)

Holly Bidle stands inside the mine accessible from her home’s laundry room. (Courtesy of Holly Bidle)

Holly Bidle and her former husband Jim Reed fell in love with the house on Mt. Zion Road in Golden the minute they learned about the mine entrance from the house’s laundry room. Never mind the building’s peeling paint, the rusting elevator in the yard, or the creepy trophy mounts that covered the walls of almost every room.

“It had been on the market for about 18 months without getting a single offer,” says Bidle (rhymes with “riddle”), recalling the day in 1990 when she first saw the house. “It was out of our price range and it needed a huge amount of work, which we couldn’t afford and had no time to do ourselves. We were running a business. We had a two-year-old and a four-year-old. It was totally impractical.”

But it was the only house in the neighborhood—or anywhere else—with a back door that opened on a mine tunnel. And that cinched the deal. “We had to have that house,” Bidle says, “because of the mine.”

Their attraction to the property had nothing to do with the mine’s ores, which were worthless, and everything to do with its history. Built in 1906, the mine was established by the Colorado School of Mines to serve as an instructional facility for mining students. Its purpose, according to a Colorado Transcript article announcing the mine’s construction, was to conduct “critical and comparative studies of processes and machines” and to “solv[e] problems in mining engineering which the mining companies have neither time nor opportunity to investigate.”

The mine’s history proved irresistible to Holly and Jim, who were themselves innovators in the field of mining technology. In 1983 they founded RockWare, which developed one of the first commercially viable software packages for geological modeling. By 1990, when they bought the Mt. Zion house, their flagship product (RockWorks) was beginning to emerge as an industry standard for mineral and petroleum exploration.

The couple purchased the property from Louise Rohwer, who had built the home with her husband, Rolfe, in the late 1950s. Rolfe Rohwer ’50 was a Mines graduate who made his living as a geological engineer. It’s not clear how he came to purchase the property, nor where he dreamed up the idea to attach a house to the front of the mine. But his unusual abode drew a brief mention in the June 1960 issue of Mines magazine:

Rolf Rohwer, ’50, is the envy of all Miners, for he can boast of having his own private mine tunnel connected directly to his house. . . . The Rohwers built their home at the entrance of the old school mine which was used by Colorado School of Mines mining students before the Experimental Mine was established in Idaho Springs.

Holly and Jim may have elicited more sympathy than envy when they took possession of the rundown building in 1990. They gradually made the house livable, while fixing up the mine tunnel with new lighting, decorations, and artifact displays, and their two young sons enjoyed the coolest playhouse and hideaway any kids could ask for.

“We had most of their birthday parties back in the mine,” Bidle says. “They’d have all their friends over, we’d lay down a tarp, and they’d roll out their sleeping bags and sleep over—right there in the mine.” Holly also extended an annual invitation to her kids’ school classes, from kindergarten through high school, for field trips in the mine.

Well lit and just a few hundred feet long, the tunnel was perfectly safe for her children to explore on their own. Bidle can only recall one time when the mine posed any danger, and that was self-inflicted. “When one of my sons was in high school, he went back there with one of his friends and they tried to set off a Molotov cocktail,” she says. “Luckily, they didn’t really know what they were doing. It wasn’t much of an explosion.”

The house currently owned by Holly Bidle was built into the side of Mount Zion. Through this entrance and to the left is the tunnel leading into the mine that was once used by Mines students. (Courtesy of Holly Bidle)

The house currently owned by Holly Bidle was built into the side of Mount Zion. Through this entrance and to the left is the tunnel leading into the mine that was once used by Mines students. (Courtesy of Holly Bidle)

A few years ago, with her boys grown and the house largely vacant, Bidle began renting out spare rooms to Mines students from overseas through a service called Interlink. That led to her decision in 2014 to open her home to tourists. She listed her home on the online booking service Airbnb, becoming the only property in the company’s vast database that includes a mine tour as an amenity.

“We have a great view, too,” says Bidle, standing on her brick deck overlooking Golden and the Clear Creek valley. “But so do lots of places. People don’t stay here because of the view. They like to stay here because of the mine.”

Bidle personally guides each guest through the mine, eliciting responses that vary from delight to curiosity to mild phobia. She points out the tunnel’s ventilation tube and drainage features; a collection of safety gear (not vintage) that includes hard hats, lanterns, and utility belts; and a wooden beer barrel from the Coors Brewery. Visitors also get a quick primer on early 20th century mining as she points out drill holes, anchor points, and other features of the instructional mine.

Naturally, the tour includes some lessons on the tunnel’s geology. “That’s one of the major things they used to teach the students back in the day—how to follow a fault,” she says. “There are no precious metal veins here, it’s just gneiss. But the principle is the same.”

Word seems to have gotten around about the unique lodging. Earlier this year, Bidle’s house claimed the top spot among Golden Properties listed in Airbnb’s search engine. “People come from all over,” Bidle says. “Some of them are parents of Mines students. I’ve had people from the Western Slope who are over here on business. I’ve had hikers staying here. I’ve had people who are in town for concerts at Red Rocks.”

Guests from as far away as Denmark and China have booked a stay in Bidle’s home and toured the old instructional mine. Each time she opens the laundry room door to reveal the dark tunnel beyond, she enjoys a brief flash of her own excitement the first time she saw the house back in 1990.

“People’s jaws just drop,” she says with a smile. “They’ve never seen anything like it.”