Menefee Mountain, Colo. - Piles of coal left over from historical mines are burning here, ignited by last summer's Weber Fire that torched 10,000 acres of forest southeast of Mancos.
Investigators have known about one small coal fire started by the Weber Fire but found more this month at scattered coal mines dating from the 1920s and 1930s.
"Coal mining on Menefee is turning out to be more extensive than anyone thought," said Steve Renner, project manager for the Colorado Division of Reclamation, Mining and Safety (DRMS).
So far, officials have identified four coal-mine refuse piles and three natural coal seams that are smoldering. The coal fires are scattered on private, state and BLM lands in steep, rugged terrain along Menefee Mountain and around Flint Rock Point.
The coal burns do not have open flames, but are a concern, especially as fire season begins. Fire and mining officials are forming a plan to extinguish them, and are continuing to search for more.
"The more we walked around and evaluated, the more we realized the fires are more disparate, so we took a step back to form a larger plan of action," Renner said.
The multiple sites of simmering coal are belching small, but steady, streams of acrid smoke, and are generating surface heat of up to 600 degrees Fahrenheit.
"The potential that they could ignite vegetation and start another wildfire is there," said Kirstin Brown, a DRMS mine safety specialist, during a tour of the area Friday.
"The other reason to put them out is they could propagate along the coal seam and start the actual mine on fire, which could burn for decades."
Along a BLM road to the Menefee Mountain radio towers, fire crews have been clearing brush from smoldering coal piles and around a natural coal seam that is oozing a hot, black tarry substance.
"It's more of a nuisance fire, not that big of a threat, said Scott McDermid, fire management officer for the Dolores Public Lands office. "It's subterranean, so we are cutting line and keeping vegetation away from the heat source."
Scrambling up a scree slope, the tour arrived at the head of a collapsed coal mine, Mancos Hill #2, with a barely discernible refuse pile in front. There was a whiff of burning coal similar to the smell of smoke from the Durango-Silverton train.
The location of the coal fire here is not obvious. But the ground just under the surface is hot, and dried oak brush and pine trees surround the site.
"You can see where it burned some of the vegetation here," Brown pointed out, and several shrubs are tagged for removal.
Long fissures can be seen in the scree and leftover coal pile, a phenomenon of coal refuse fires, explained Kay Zillich, a BLM abandoned mine specialist.
"What happens is under the soil surface, the coal burns away, leaving an unstable layer underneath forming fissures. It is the same way a charcoal briquette retains its shape after it has completely burned," she said.
An unwary hiker could step on what looks like solid ground, but break through the crust, fall several feet and into a searing hot coal oven.
Rattlesnakes, on the other hand, are known to cozy up to coal fires to get warm.
Miners used hard-rock mining techniques to extract the low-grade coal from this Menefee Formation, Brown said. A "room and pillar" system left columns of coal in place while rooms were excavated out around them. Coal was then transported to market via the Rio Grande Southern railroad.
FIRE CONTROL PLAN
Federal fire and state mining officials are collaborating to extinguish the Menefee coal fires, expected to cost at least $200,000. Excavators will be brought in to dig up the coal, and then a special fire retardant foam mixed with water will be applied.
Once the soil temperature is below 100 F, the area will graded and contoured to the natural slope.
Initially, the Colorado Division of Reclamation Mine and Safety submitted a plan to do the work in May, but the discovery of multiple coal fires in steep terrain away from roads complicated the cleanup and pushed back the fire mitigation plan until later this summer.
An aerial, infrared survey was done last week to help map the scattered coal fires.
"Characterizing it as a fire is exaggerating; it is more of pre-heating," Renner said. "These are not difficult to put out. If left alone, they generally move a couple of inches per year. The biggest expense it going to be accessing the remote sites with equipment."
There are 34 coal fires burning in the state, Brown said, and they can smolder for decades. Mitigation is done on a case by case basis, but many are in coal seams that run so far underground that they cannot be reached effectively.
"They can be a problem. It is thought that a coal fire started the Glenwood Springs fire (Coal Seam Fire, 2002), and there are still coal fires burning over there," she said.