GUNNISON & PITKIN COUNTIES — The Colorado Department of Transportation and contractor Geovert will begin a project on Monday, April 19, to mitigate the risk of rockfall along Colorado Highway 133 between the McClure Pass summit and Carbondale. Work will take place at five separate sites and is scheduled for completion by mid-October 2021.
“Rockfall mitigation is one of the best ways to maintain safety on Colorado’s rural highways,” Executive Director Shoshana Lew said. “We are excited we can get critical work done on this busy local highway, which is popular with locals and tourists.”
The project will include rock scaling (bringing loose surface material down with pry bars or other equipment) and stabilization; rock excavation and blasting; rockfall wire mesh installation; and construction of a rockfall catchment structure. This project also includes erosion control and localized highway repair at each of the five sites between Mile Points 48 and 60, which is located south of Carbondale. Crews will also grading at the Placita rock disposal site near the northern base of the pass (at MP 47). Travelers can expect full traffic stops of up to 20 minutes at one or two sites during most weekdays (delays will extend beyond the full stop, as queues are cleared in each direction). Please see further details below for maps of where work will take place.
“CO 133 over McClure Pass has been a priority for rockfall mitigation in the area,” Regional Transportation Director Mike Goolsby said. “We appreciate the patience of residents and visitors as CDOT completes this important work.”
Specifically, work and travel impacts will take place at the following sites:
- Placita Disposal Site, MP 47.1 – Trucks will be entering and exiting here, causing intermittent traffic slowing and brief stops
- Hunter’s Loop Cut, MP 48 – This site requires blasting of rock material; the work will involve drilling into rock, initially, followed by blasting, likely over a two- to three-day period in late August or early September. There will be one to two periods of midday blasting each of those days, during which time motorists will be fully stopped in both directions for up to one hour, followed by clearing of traffic in each direction. The public will be notified of these periods of extensive delays for blasting at least one week prior, including messages on project signage. The hillside will be further stabilized with the installation of 25-foot-long rock bolts, heavy-gauge cable mesh and a lighter-gauge draped mesh (hung with the use of a crane).
- Firehouse, MP 52.6 – Work will involve rock scaling (bringing loose material down with pry bars and other equipment), additional excavation with a hammer excavator, and draped mesh.
- Penny Hot Springs MP 55.2 – Work here requires crews to build a gravity wall, a concrete-faced, gravel rock-filled wall, approximately 21-feet tall, 12-feet thick and 425-feet long, to contain rockfall material.
- Gray Cut MP 60.20 / Nettles MP 60.3 – These adjacent sites will receive the same mitigation treatment as the Firehouse site, above. The Nettles site will include 15-foot-long rock dowels and a reinforced shotcrete (sprayed concrete) buttress to retain a large boulder.