VIDEO: Amidst the sweet-smelling smoke of ponderosa pine, wildland firefighters are laboring to maintain – not extinguish – a wildfire burning in the Coconino National Forest northeast of Flagstaff. Their work is made more complicated by two factors: unusual volcanic soil and a “no-go zone”: a decommissioned artillery range the Army suspects contains unexploded ordnance from the 1940s and ’50s. On the firefighters’ 15,000-acre planning map, the zone is marked with a large black circle. After the lightning-caused Maroon Fire was detected May 16, the U.S. Forest Service decided to control and manage the fire rather than put it out. About 8,600 acres had burned as of this week. The Forest Service has been letting wildfires burn more often, when humans aren’t endangered. “We live in a fire adapted ecosystem in northern Arizona,” said Aaron Graeser, who’s an incident management team commander on the Maroon Fire. “Fire is a natural part of the way this ecosystem functions and should function.”