Explosive Target Identified as Culprit Behind 46,000-Acre Sawmill Inferno

The Sawmill Fire, which scorched 46,000 acres of state trust land south of Tucson, was ignited by recreational shooting with an exploding target, as confirmed by the Star. An off-duty Border Patrol agent was engaged in target practice when the fire started, even though shooting is typically not allowed on state lands.

Regulations stipulate that firearm discharge is permitted only during lawful hunting activities. However, the Arizona State Land Department has remained silent on the specific status of exploding targets on their lands, despite them being banned on U.S. Forest Service and Bureau of Land Management areas in the region.

Officials estimate that fighting the Sawmill Fire cost approximately $5 million. The blaze erupted on April 23, shortly after 10:58 a.m., propelled by winds gusting up to 40 miles per hour. Chuck Wunder, chief of the Green Valley Fire Department, highlighted the severity of the conditions, prompting a fire watch from the National Weather Service.

Responding units arrived just minutes after the fire ignited, already witnessing flames that covered 300 acres. Ultimately, the inferno spread beyond the Santa Rita Mountains towards the historic Empire Ranch and surrounding Las Cienegas National Conservation Area. Despite escaping structural damage, the blaze prompted pre-evacuation notices for nearby residents and posed a significant threat to homes and infrastructure for several days.

Investigative efforts are underway, led by the Forest Service. However, details surrounding the fire’s cause remain under wraps as agencies have been hesitant to divulge information. A Freedom of Information Act request from the Star for documentation related to the fire has been met with resistance, as the Pima County Sheriff’s Department indicated a legal review is required before any records are released.

Moreover, a separate brush fire on April 4 on Mount Lemmon was linked to recreational shooting as well. The Forest Service is currently searching for a person of interest related to that blaze. In this case, the off-duty Border Patrol agent responsible for the Sawmill Fire was proactive in alerting authorities.

The explosive target used in this incident contained Tannerite, a mixture of ammonium nitrate and aluminum powder. It is typically sold in two separate components, which only become explosive once combined. Though the individual components can be transported without permits, the mixed product is regulated and requires appropriate licenses from the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives.

The increasing incidence of fires linked to exploding targets has raised alarms among fire management agencies. Recent reports indicate that these types of targets have been connected to over a dozen wildfires across the western United States in recent years.