Crews recently began work to extinguish a blaze that has burned underground for more than a century.
It’s happening on Marshall Mesa, south of Boulder, in an area popular with hikers. A fire in a coal seam there has been smoldering beneath the surface for years. It’s a remnant of a time when coal mining thrived in the area.
Because heat from underground blazes can sometimes set fire to grass and other brush, residents of the nearby towns of Superior and Louisville have been more concerned about potential dangers since the Marshall Fire…