‘Ruby Gravity Attack’ Tested Mettle of CDOT Crews, Local Economies
by Samantha Wright
Feb 13, 2014 | 1330 views | 0 0 comments | 48 48 recommendations | email to a friend | print
RED MOUNTAIN PASS REPAIR – Workers with Colorado Department of Transportation and Yenter Companies have raced against the clock in often brutal weather conditions to install a rockfall fence along the hazard area. (Photo courtesy of CDOT)
RED MOUNTAIN PASS REPAIR – Workers with Colorado Department of Transportation and Yenter Companies have raced against the clock in often brutal weather conditions to install a rockfall fence along the hazard area. (Photo courtesy of CDOT)

WESTERN SAN JUANS – A month after a huge rockslide shut down U.S. 550/ Red Mountain Pass between Ouray and Silverton, the highway has finally completely reopened, allowing traffic and economic lifeblood to once more flow along the transportation artery between the two communities. 

Intermittent travel twice a day has been possible since the end of January, but it wasn’t until Monday night, Feb. 10 that the Colorado Department of Transportation reopened the roadway up to traffic 24/7, with single-lane, alternating travel controlled by traffic signals. 

Crews from CDOT and its rockfall mitigation contractor Yenter Companies put in a long, grueling day on Monday, laboring in blizzard conditions to finish a 360-foot rockfall fence in the hazard area, locally known as the Ruby Walls, where the highway cuts into sheer ruddy-colored cliffs over a thousand feet high.

The rockfall mitigation project has been fraught with danger – rockfall, ice fall, high-angle exposure, and at times fiercely wintery conditions – as crews raced to reopen the highway and restore full access to the communities of Silverton and Ouray.  

“We are relieved for sure to get it done,” CDOT Project Engineer Tim Webb said. 



The ordeal began on Sunday evening, Jan. 12 when it began “raining rocks” at mile marker 90 on U.S. 550/ Red Mountain Pass. Crews cleared the highway and reopened it to travel that night, but as a steady stream of rubble continued to pour down on the roadway the next day, CDOT officials made the decision to close the highway again. It would remain fully closed for the next two and a half weeks – the longest closure due to rockfall that anyone can remember. 

CDOT geologists discovered that the slide had initiated from a near-vertical rock slope 900 feet above mile marker 90, when a slab of rock the size of a football field broke free from the surrounding rock and fractured into smaller pieces of rock rubble. After the initial release, thousands of tons of material remained perched on the cliff face, endangering motorists down below.  

The first step toward reopening the highway was to mitigate as much of this rockfall hazard as possible, first by scaling the largest rocks off the slope, then bolting panels of wire mesh netting over the remaining debris to pin it in place and prevent it from cascading onto the highway below. 

This effort took about 10 days, during which the weather remained improbably sunny. 

Local climbing and rigging experts from both Rigging for Rescue in Ouray and Silverton Mountain ski area made “tremendous contributions” to the project, Webb said. 

Rigging for Rescue owner Mike Gibbs, with whom CDOT contracted to act as mountain safety officer and rigging coordinator for the project, vividly documented the experience through daily blog posts on his website.

 “There were days when it felt dangerous up there,” he said. “We were definitely aware we were in high hazard environment. There were elements of tension and fatigue, and the rawness of the environment.”

It was delicate and dangerous work, both for the crews stationed on the cliff face as well as for the helicopter pilots from Silverton Mountain and Helitrax, who delivered almost 40 bundles of wire mesh netting from a staging area at Ironton Park to the Ruby Walls, where workers then anchored it into place over the shifting debris. 

“We absolutely transformed that slope,” Gibbs said. “What Mother Nature would have taken 10,000 years to do, we did in 10 days. Now, after a week or so of reflection, I am just super-grateful no one got hurt.” 

The perfect safety record was due to both good fortune and good planning, Gibbs said. “We were diligent in our safety preparation and exposure to hazard. I am proud of our significant contributions toward getting the highway open.” 

Highly skilled guides from Silverton Mountain worked side by side with their counterparts from Rigging for Rescue and Yenter Companies to get the job done. 

“We were so grateful CDOT let us help,” Silverton Mountain co-owner Jen Brill said. 

CDOT was equally grateful for their contributions. 

“Those Rigging for Rescue and Silverton Mountain crews were very much needed,” Webb said. “Yenter, Silverton Mountain and Rigging for Rescue were all skilled in high angle construction methods. They worked very well together.” 

The first phase of the mitigation project wrapped up on the last sunny day before a series of storms hit the region in late January.

“That night, we got the guys off the slope,” Webb said. “The next day, CDOT closely observed the work that had been done, to make sure conditions were safe before moving forward with limited daily highway openings.”

The Silverton mail truck was the first vehicle allowed through. Then, on Jan. 31, CDOT deemed the highway safe enough for intermittent travel twice a day in the early morning and late afternoon. CDOT and Yenter then shifted into the next phase of the mitigation project –installing a temporary metal mesh fence along the highway to protect motorists from rocks that might continue to cascade down.

Every day presented different challenges. While warm temperatures brought risk of rockfall and icefall, cold temperatures caused the equipment to freeze up. Then there was the practical problem of keeping water in the grout pumps from freezing. Workers had to use torches to keep it in a liquid state. 

“Our goal was to get out as safely and quickly as possible, and get our men out of the danger zone,” Webb said. “This is not for the faint of heart, to be on this crew.”



The 360-foot-long structure that CDOT has just completed installing is not your ordinary garden-variety chain-link fence.

“It is a very large-scale fence, and it has been built safely to accomplish the task of protecting the road from rocks,” Webb said.

Ten steel I-beams – each 25 feet long and weighing 1,500 pounds – serve as the “fence posts.” They angle out over the roadway by about 20 degrees, and are tied back into the cliff face with 1-inch thick steel cables and rock anchors. 

Two horizontal rows of cable netting are attached to the beams. Each panel is 72 feet long and 12 feet wide. The netting gets its strength from 5/16th inch thick steel cables that are interwoven through the metal mesh in a criss-crossing pattern that is designed to prevent large rocks from punching through. 

The fence is a temporary measure, until CDOT is able to come up with a more permanent design and solution for the rockfall area. For now, single-lane, alternating travel controlled by traffic signals at either end of the hazard area will be the rule of the road. 

“This is not for a couple of weeks,” Webb emphasized. “The fence will be here for this winter and into next summer, for sure.” 

Even with all the mitigation that has taken place, “There is still potential risk,” Webb added. “That is just the nature of this place. It is more risky now than it was before the rockslide. The netting won’t keep every rock from coming down.”



There was a deep, profound weariness in Greg Stacy’s voice when The Watch reached him for a phone interview on Tuesday this week, the first day Red Mountain Pass had fully reopened to traffic. As the incident commander of the rockfall mitigation project, Stacy has been putting in 100-hour weeks since the Ruby Walls released its load on Jan. 12.

Stacy now works as CDOT deputy maintenance superintendent for the Durango section, but before that, he was CDOT’s regional boss for the area that encompasses Red Mountain Pass, so he’s seen the Ruby Walls do its thing before. But never on this scale.

“The whole incident was unprecedented in my career and that of anybody that I know,” he said. “The scale of the rockfall, the extreme environment, the topography, the geology, the weather, everything. It was a herculean effort. I am happy with the way it turned out. We were just lucky we were in Colorado and we had the people to do it; all the experts were here.”

Stacy estimates the project will have cost CDOT upwards of $1 million, once all is said and done. It is trickier to estimate the economic ramifications of the highway closure on the communities of Silverton and Ouray. Both towns found themselves stuck at the terminus of dead-end roads for almost a whole month. Without the economic lifeblood provided by the estimated 2,000-plus motorists per day that typically traverse Red Mountain Pass at this time of year, Main Street businesses in both towns report that they have been struggling to stay afloat.

“Dead as a dog,” was the phrase that one Ouray restaurateur used to describe the situation.

Ouray’s Hot Springs Pool saw a 20 percent decline in visitors over the month-long highway closure compared to the same time period last year, although City Resource Manager Rick Noll, who tracks these numbers, emphasized it was not possible to absolutely pin that decline on the highway’s closure. 

The Ouray Ice Park stayed as busy as usual, according to OIPI President Mike MacLeod, but Silverton Mountain, the primary engine of Silverton’s winter economy, reported a drastic decline in business. 

“It was a state of emergency here as far as we were concerned,” Brill said. “On one day during the full closure we had eight skiers on a day when we typically would have had 60 to 80. That’s like not anything we have seen since we were only allowed 20 skiers a day when we first opened in 2002.”

Now, with the highway once again reopen, things are already looking up. Skier numbers at Silverton Mountain were back to normal last weekend. And the Backstreet Bistro in Ouray, which reported a 50 percent drop in business in recent weeks compared to the same time period last year, was so busy this Tuesday that they almost ran out of chili. 

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