A team of investigators from the U.S. Forest Service's law enforcement wing worked Tuesday to determine the cause of a wildfire between Flagstaff and Sedona, relying in part on dozens of tips from callers.
Coconino National Forest spokesman Brady Smith said federal officials could not reveal details of the investigation but believe the fire is human-caused. The five-person team was at the scene of the blaze.
"They feel good about the progress that they've made so far," Smith said.
The Slide Fire has burned about 20, 369 acres and continues to grow, stifling tourism in parts of the Sedona area, which usually is busy with visitors this time of year. Slide Rock State Park, one of Arizona's most-visited tourist spots, has been closed since the fire began May 20.
Smith says investigators have received about 80 tips from callers. It could still take months for them to pinpoint exactly how the fire began.
"It really depends on the types of tips that we get in and the information we're able to gather right off the bat," Smith said. "Some fires go unsolved forever."
Dick Mangan, a retired Forest Service safety official who is now a wildfire consultant, said investigations into the origins of wildfires like the one in northern Arizona usually require vast resources.
"The basic concept is, first of all, to try to figure out where the fire probably started and literally keep all of your options open," Mangan said. "Just because there was a logging operation there doesn't mean it was a logger. Just because it was near a campground doesn't mean it was a camper.
"You try to go into it with a clean sheet of music and use a process of elimination."
Mangan said investigations can sometimes cost more money than actual fire suppression, and officials usually go after the perpetrators if they find one.
If Slide Fire investigators are able to track down whoever is responsible for the blaze, federal officials likely would arrest them and turn over the case to prosecutors.
They probably would seek to recuperate the costs of fighting the fire, Mangan said.
More than 1,000 firefighters have worked on the Slide Fire, which has threatened 300 structures and caused evacuations in Oak Creek Canyon from Slide Rock State Park to Sterling Springs Hatchery.
No homes have been destroyed.
Crews established a containment line around the entire fire by Tuesday. However, the official containment figure remained at 45 percent because some areas still had active low-intensity fire while others remained hot to the touch.
Fire managers were working to protect the threatened structures, keep the fire from pushing into the communities of Forest Highlands and Kachina Village to the east, and minimize the potential for flooding.