CDOT Begins Rockfall Project on SH 133 McClure Pass

September 11, 2012 - Northwestern Colorado/CDOT Region 3 - PITKIN/GUNNISON COUNTIES – The Colorado Department of Transportation will begin a project on Monday, September 17, to reduce the potential for rockfall on SH 133 over McClure Pass.

The rockfall mitigation consists clearing rock debris from the roadside ditch, scaling rock from the hillside (bringing rocks down with air bags inserted behind loose rock and also bringing down by hand), installing rock reinforcement (with dowels and also a concrete mixture), and anchoring and installing wire mesh (or cable netting) to contain smaller rocks. The work will be done on the north side of the pass near Marble, between mileposts 44 and 49.

TRAVEL IMPACTS: During periods of rock scaling work (done each day), traffic will be stopped in both directions for up to 20 minutes. Delays may exceed 20 minutes as traffic queues are cleared in both directions. When scaling is not underway, travelers should still anticipate some delays and single-lane, alternating traffic, Monday through Friday (and some Saturdays) during daylight hours.

There will be a winter suspension of work likely starting around November 1. The project will resume in April 2013 and will be completed in July 2013.

“McClure site is ranked at the top of our Rockfall Hazard Rating System,” said Ty Ortiz, CDOT rockfall specialist. “The amount of rockfall we see here on an annual basis is quite a bit higher than what we see in many other sites around the state.”

CDOT contracted the work to TK Mining for $2 million.

For information on CDOT projects statewide, the public may log on to or call 511.) Better yet, sign up for highway updates by going to and choosing the green cell phone icon in the upper right corner. Thank you for going Slow for the Cone Zone!

*CDOT’s Rockfall Program
The Colorado Rockfall Hazard Rating System (CRHRS) sites are ordered in funding priority from 1, which has the highest combination of hazard and risk, to 756 which has the lowest. To determine which sites are of high priority, several factors are analyzed including slope profile, geological characteristics and traffic data.

The rockfall program, started in 1996, was created to track rockfall information, implement a rating system and mitigate potential hazardous areas.  When the program first began, CDOT received just $750,000 for projects statewide. Since that time, funding for the Rockfall Program steadily increased to accommodate rising construction costs and allow for additional mitigation across the state. In recent years, the program was receiving $3 to $5 million per year. For the 2012-13 seasons, the program is receiving about $7 million—which includes $2 million in State Transportation Commission contingency funds that will help supplement projects statewide.

Since the program began, about 70 sites have been mitigated through CDOT’s Rockfall Program.  CDOT rockfall specialists also provide additional assistance at nearly 30-40 locations statewide each year in response to rockfall and other activity.