Colorado mitigation work to address coal smoldering underground at Marshall Mesa Trailhead complete
Officials from the Division of Mining Reclamation and Safety say extensive mitigation efforts in Colorado to address burning and smoldering coal from a former mine beneath the Marshall Mesa Trailhead have been completed.
The site, located just south of Boulder, has now been fully excavated, the division announced on Monday. More than 180,000 cubic yards of material were removed, and areas that had been burned out already and "posed a risk of surface subsidence" were dealt with.
Three years ago the Marshall Fire started very close to the trailhead, but it was determined that underground fires didn't start the destructive blaze. Much attention was paid to the underground fires in the area, however, and the Marshall Coal Fire Mitigation project was launched. During the excavation work, the division says they recorded some high subsurface temperatures -- usually between 175 and 250 degrees. The highest reading they recorded was 525 degrees in one spot.
All that's left now before the project can be completed is some grading and backfilling work. That should be done in about a month. A project to redevelop the trailhead will be launched in the spring.