Plan for new Glenwood Cavern tour starts with specialized survey work
December 24, 2007
GLENWOOD SPRINGS ” A casual observer looking at a hillside at Glenwood Caverns Adventure Park sees only that – a hillside.
Park owner Steve Beckley stares at the same hillside as if with X-ray vision, peering inside Iron Mountain, and also into the future.
Just across from the Canyon Flyer alpine coaster attraction, a surveying stake sits up the hill. Underground, 27 feet below the stake, lies the “Penalty Box,” one of several rooms in the cave system that Beckley hopes one day to make accessible to the general public.
“So you could have a new cave tour, starting digging right here,” Beckley says, pointing to the slope on a recent Sunday afternoon.
His hope is to build a tunnel that eventually could be anywhere from 150 to 300 feet in length and allow for family tours to several new rooms in Glenwood Caverns. The current family tour, leading to the giant and formation-filled rooms of King’s Row and the Barn, is at capacity all summer, drawing more than 700 people a day. Being able to offer a new tour would be a big way of drawing back previous visitors to what has grown since its opening in 1999 into one of the top attractions in the tourist town of Glenwood Springs.
But tunneling into a cave isn’t just a matter of powering up drilling machines and lighting dynamite fuses. Beckley also has to know in what direction to dig the tunnel. And figuring out where underground caverns are located when viewed from the surface is no simple matter.
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That’s where a team of experts with some technological know-how were able to help out Beckley on this recent weekend.
Bob Buecher came up from Tucson, bringing a beacon that can be set inside a cave, where it emits very-low-frequency signals that are read from the surface. Using earphones and antenna wires wound around wooden wheels to capture the signals, Buecher can locate the spot directly above the beacon in the cave, and also take a measurement from a fixed, nearby point so calculations can be applied to determine its depth.
Buecher also used the technology in helping plan for the development of the Kartchner Caverns, an Arizona state park.
“They had to put in a $10 million tunnel. They really wanted to know where the other end would be,” Buecher said.
Still, it’s easy to make big mistakes with cave surveying, Buecher said. Being off by even 10 feet can mean missing an entire passageway.
Glenwood Caverns is mapped out with thousands of survey data points, but the mapping requires lots of crawling, and it’s hard to be totally accurate. Trying to correlate the surveyed underground locations with surface locations adds another layer of complexity. The beacon system is intended to confirm other surveying efforts or help correct them where they are wrong.
However, using the beacons requires teams working in tandem both above and below ground. A cave team must place the beacon in the right location and alert the surface group when it’s time to take readings, and that group needs to be able to tell the cavers when their job is done. But it’s not as if the two teams can shout instructions to each other, or wait for a messenger to scurry back and forth when getting in and out of cave rooms sometimes can take hours.
That’s where other helpful technology comes in. Lakewood resident Mike Doe also was on hand during the recent surveying project, with specialized radio equipment that can penetrate 1,000 feet of rock. Each team carries a collapsible antenna and converted CB radio to allow for two-way communications.
“It makes everything so much easier and more coordinated,” Doe said.
During their recent visit, Doe, Buecher and others demonstrated how the two technologies work in harmony. Bundled up on a sunny but crisp afternoon, they plodded around a slope in calf-deep snow while taking readings from a beacon deployed by a four-person crew in “The Canyon,” a room located some 60 feet below them.
As I found out later, the underground team labored in warmer conditions, but challenging in their own right. After they surfaced from The Canyon, I joined three of them in heading to another room named “Polar Bar.”
We had hardly stepped underground before we were slithering through openings little wider than our bodies, our progress slowed by the need to push packs and the wheel-like beacon through the same crevices. Glenwood Caverns employee Wade Beattie led us along, but he hadn’t been to the Polar Bar before. So we found the cave radio to come in handy when we got to a point that Beattie knew was close to the room, but he wasn’t sure which way to safely proceed. All it took to confirm the right route was setting up the cave radio to make a call to the surface, and soon we had arrived at the proper place to put the beacon.
Polar Bar gets its name from calcite that water eroded from limestone and deposited in solutions throughout the room, including in stacked layers that are exposed in the walls.
Beckley would love to be able to make it easier to get to places such as the Polar Bar and Penalty Box that are accessible now only by lots of dark and dirty crawling and slithering. He also would like to create a passage for tourists to be able to conveniently visit Discovery Glen, which lies below Penalty Box and is one of the larger known rooms in Glenwood Caverns. Beckley found Discovery Glen on the same day in 1998 that John Glenn returned to space. Beckley is interested in setting up an interpretive show with lighting and sounds that would tell the story of how the Colorado River once flowed at the level of Discovery Glen, and hot springs later bubbled up there, factors that contributed to how it looks today.
Finding a route to tunnel through solid rock to some of the caverns’ formations would cause less impact than widening cave passages. A tunnel also expedites the delivery of materials needed to set up new tours, and allows for installation of airtight doors that help maintain the moisture that is responsible for so many of the cave formations.
Other technology such as ground-penetrating radar and electronic resistivity testing also may help Beckley in mapping out rooms and passages as they relate to the surface, and even detecting new cavities in a system that he believes extends much farther than its known three miles of passageways. He hopes to decide on a new tour and open it up in the next 18 months or so. He said the hardest challenge isn’t the surveying, but getting a good cost estimate because the project involves so many unknowns.
For now, he’s getting some answers to his surveying questions. Beckley was happy about how the recent measurements were in keeping with his understanding of how rooms could be reached by a tunnel from the surface.
“It looks great,” he said as the survey teams prepared to head down Iron Mountain after a day’s work that had lasted until it was nearly as dark outside as in the caverns. “All those things line up with what we were expecting.”