Four massive wildfires, nearly 1 million acres and more than 800 homes. And all in three years. Much as a snowball increases in speed and size as it rolls down a mountain, Arizona wildfires are growing larger and more destructive over time.
Mirroring national trends, wildfires in Arizona have continued to break records since 2002, a year of infamy for residents of the eastern part of the state, where the humancaused Rodeo-Chediski fire laid waste to 491 homes and nearly 470,000 acres.
That fire remains the biggest in the state, followed by this summer’s Cave Creek Complex fire, which charred more than 248,000 acres of Sonoran Desert and destroyed 11 of 44 homes in Camp Creek, a community north of Cave Creek.
Last year’s Willow fire southwest of Payson ranks third at 119,500 acres and the Aspen fire stands fourth, having burned 84,750 acres on Mount Lemmon northeast of Tucson.
Combined, the four fires consumed more than 920,000 acres and at least 822 homes.
Almost a decade ago, the then-largest wildfire in Arizona’s history burned 61,000 acres. The record before that was a 1971 blaze that burned 57,000 acres.
Nationwide, wildfires have ravaged more than 34 million acres since 2000, according to statistics from the Idahobased National Interagency Fire Center, which pools federal, state and local resources to fight wildfires.
That’s more acres burned than any other five-year period in the country since at least 1960, according to the agency’s statistics.
Comparisons stop at 1960 because record-keeping before then may not be complete, said Rose Davis, a spokeswoman with the fire center.
Davis said the massive amount of land burned in recent years was the result of larger amounts of fuel available to hungry flames.
The accumulation of timber-choked forests can be traced to establishment of the U.S. Forest Service in 1905, and the agency’s aggressive fire-suppression efforts, she said.
From its creation until the 1980s, the Forest Service was able to keep every fire under 250,000 acres.
"We just didn’t see that whole time what we were doing was having the effect of increasing the fuels, which is why we’re having these megafires in timber areas."
The large amount of trees in the forest isn’t the only reason fires like the Rodeo-Chediski have grown so large, said Ken Palmrose, a fire prevention officer with the U.S. Bureau of Land Management.
Years of drought have weakened trees and opened them up to attack by invasive species such as the bark beetle, which has killed millions of trees in Arizona. And dead trees act like kerosene to a fire, Palmrose said.
"If there’s a spark, there’s a fire," he said.
But in the case of the Cave Creek Complex fire, heavier than normal winter rainfall actually made conditions worse, said Rick Ochoa, fire weather manager with the interagency fire center.
"That’s been to me the largest factor why we’re having wildfires in Arizona this year," he said. "The rainfall has produced more grass, more brush, and therefore more fuel."
When the wet season ended early this year, that fuel dried up and acted like gasoline when lightning struck June 21, sparking two fires that would later merge to become the Cave Creek Complex fire. The fire died down when it hit pine trees still moist from the extra wet winter.
While moisture content is out of human control, Davis said that since 2000, the U.S. Forest Service has focused on undoing decades of overzealous fire-suppression efforts.
Treatment includes more aggressively thinning forests choked with trees and performing prescribed burns.
"We’ve got a forest that’s not in its natural state, and people will argue that is, but in our minds, reducing fuels will allow fires to work in a more natural way — as the janitor of the forest."