Borehole blockage cause of loud Smuggler Mine explosions, state investigator finds |

Borehole blockage cause of loud Smuggler Mine explosions, state investigator finds

Fuse cap disposal occurred far closer to the surface than expected

Smoke and flames can be seen Saturday morning coming from the Smuggler Mine, which is east of Aspen. (Garrett Greene/Courtesy image)

After visiting the Smuggler Mine on Monday afternoon, a state investigator determined that the detonation of six old fuse caps near the mine was the source of several loud explosions that rattled Aspen on Nov. 28.

A report filed Tuesday afternoon by Bill York-Feirn, mine safety program director for the Colorado Division of Reclamation, Mining and Safety, indicates that the blasts occurred far closer to the surface than anticipated due to a blockage in the borehole where the fuse caps were detonated.

Two mine employees detonated the fuse caps (small metal tubes that contain explosives designed to detonate a larger charge) and “a small explosive booster charge” in the hole approximately a quarter-mile north-northwest of the entrance to Smuggler Mine (on the hillside above Silverlode Drive), the report stated.

But upon inspection, investigators found the hole that the mine operator had initially estimated to be 1,300 feet deep was in fact only 20 to 30 feet deep and “either partially or fully blocked,” the report indicates.

Because of the blockage, a detonation that might have occurred nearly a quarter-mile underground instead happened just 10 yards below the surface, shooting flames and debris out of the hole and scattering debris up 30-40 feet from the hole, York-Feirn reported. The hole is approximately one foot in diameter and collared in steel pipe.

“An initial explosion was heard followed quickly by a louder, more substantial explosion that shot broken rock and old mining pipe out of the hole,” York-Feirn wrote in the report. “Flames were seen coming from the hole which created a smoke plume.”

“It is likely the explosives hung up in the hole or collected with other old explosives and created a larger detonation much closer to the surface than was anticipated,” York-Feirn wrote.

Rick Balentine, fire chief for the Aspen Fire Department and one of local officials who investigated the explosion Monday, said that the hole has been a detonation site for the mine for decades.

“They’ve been using this particular spot … for 40 years that I know of,” Balentine said.

The fire department plans to issue a full report Wednesday, Balentine said. He expects that update to report information similar to the details in York-Feirn’s account and will likely conclude the department’s investigation.

At this time, no further action from the state is expected. The disposal of blaster caps, which include the fuse caps detonated on Saturday, is under the jurisdiction of the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives, not the Division of Reclamation, Mining and Safety. (York-Feirn was dispatched to investigate because the Smuggler Mine holds an active tourist mine permit through the division, as previously reported.)

Matthew Deasaro, acting public information officer for the Denver Field Division of the bureau, could not be reached for comment on Tuesday evening.

And as for James Corcoran, the eyewitness who expressed concerns about the explosion in conversations Monday with The Times, the state investigator’s report addresses some of the questions Corcoran felt were unanswered over the weekend.

“This is seriously reassuring,” Corcoran said Tuesday evening. “This is the one believable weird thing that happened.”

Kaya Williams can be reached at

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