Authorities for months have blamed Arizona's largest known wildfire on an unattended campfire that got out of hand.

On Wednesday, they put names to the campers they say are responsible, charging two cousins from southern Arizona with sparking the Wallow Fire.

Caleb Joshua Malboeuf, 26, of Benson, and David Wayne Malboeuf, 24, of Tucson, were charged with five low-level federal offenses related to the campfire they started in late May and are alleged to have not extinguished properly.

Arizona wildfire: Wallow Fire near Alpine

The blaze charred more than 538,000 acres in eastern Arizona, destroying 32 homes, four businesses and more than 30 barns, sheds and other buildings during the six weeks that it burned out of control in the Apache National Forest.

The blaze cost more than $79 million to suppress, according to court records, and took a heavy toll on the mountain hamlet of Greer, where 21 homes were lost. As it moved through the forest, the fire nearly destroyed the communities of Alpine, Nutrioso and Eagar along the way.

As residents there continue to clean up from the fire and floods that followed, Wednesday's announcement that two men would be charged in connection with the blaze left many residents pondering how much liability the campers should bear. And questions over whether the Forest Service reacted quickly enough to the fire still linger.

"I don't think there's an extremist environment here in Greer, but all of us lost a lot, and we want answers to those questions," said Roy Laos, a full-time Greer resident. "Whether it's through the Forest Service or through the adjudication process, all we want is the truth."

Blaze investigation

The Malboeufs are scheduled to make an initial appearance Sept. 19 in U.S. District Court in Flagstaff.

The charges relate to federal offenses of starting a wildfire on federal land, leaving a campfire unattended and failing to extinguish or remove flammable material from the area near the campfire. Each of the five offenses carries with it a penalty of up to six months in prison, a $5,000 fine or both, the U.S. Attorney's Office said.

The circumstances that led to the Wallow Fire are detailed in a federal criminal complaint unsealed Wednesday. The complaint is based in large part on statements the Malboeufs made to investigators during interviews conducted immediately after the fire and through the summer.

The Malboeufs arrived in the Bear Wallow Wilderness with their two dogs on the Saturday of Memorial Day weekend, setting up camp near a creek that night where they cooked dinner over a campfire. The fire was in a ring, according to court documents, and the campers let it go out on its own that night. They lit it again the following morning to make breakfast.

The cousins told investigators that they remained in camp for several hours and, assuming the fire was out, embarked on a hike while leaving their blue heeler dogs and camping equipment behind.

"They stated that they believed their campfire was out because David threw a candy wrapper in the fire just prior to their departure, and it did not melt," court documents said.

But when they were returning to their campsite several hours later, the Malboeufs told investigators, they could smell and see smoke from the area.

"They tried to return to camp to cut their dogs loose, which they had left tied up in camp, but could not get close because of the fire and smoke," the complaint stated.

The cousins ran from the area toward the Black River where they stayed overnight, according to court documents.

The following morning they hiked to a forest road and got a ride to their car from an Apache County sheriff's deputy. The sheriff's deputy alerted a Forest Service law-enforcement officer who met the men at the campsite.

Forest Service officials continued to keep in contact with the cousins through June and July as they investigated the fire's origin, according to court records. Their stories never changed.

The Malboeufs told investigators that they are experienced campers who have made frequent trips to the Apache National Forest and that they chose their site because it looked well-used, leaving them with the impression that they did not need to clear away flammable material, according to court documents.

They did not take a shovel or bucket into the woods and had not used water or dirt to put out the fires, the complaint said.

When fire investigators returned to the scene two weeks after the fire started, they found the camping equipment the Malboeufs described and the two dogs tied to trees. One was dead and the other still alive, according to the complaint.

"There had been no attempt to clear any flammable materials from around the campfire to prevent its escape," according to court documents.

Caleb Malboeuf's mother, Mary Malboeuf, also of Benson, said Wednesday that she was shocked her son had been charged with causing the Wallow Fire.

"It is tragic," she said. "I love my son. He is a good man. . . . I just talked to him yesterday."

Response questioned

Laos said the version of events outlined in court records, including details about the candy wrapper and the dogs, had been circulating in Greer for a couple of months.

Residents there are as concerned with the U.S. Forest Service's response to the fire as they are with the actions the cousins took after discovering the blaze, Laos said, particularly because the Malboeufs contacted a sheriff's deputy the following day and were interviewed by a Forest Service agent soon thereafter.

Many in the area believe the Forest Service was slow to respond in the days after the blaze was spotted, inadvertently allowing the Wallow Fire to grow out of control.

A U.S. Forest Service spokeswoman did not return calls for comment Wednesday.

"There are a lot of factors, but the two factors we do want answers to are: Why wasn't there an early response to this fire?" Laos asked. "And how culpable are these two campers for starting the fire?"

The latter was a question that gripped northern Arizona nearly a decade ago as residents there tried to recover from what was, before the Wallow Fire, the state's biggest wildfire, Rodeo-Chediski.

Leonard Gregg, a part-time firefighter, received a 10-year prison sentence and was ordered to pay nearly $28 million in restitution for intentionally setting what became the Rodeo Fire. But Valinda Jo Elliott, whose signal fire started the Chediski portion of the blaze, was not charged because prosecutors concluded there was no criminal intent. A federal appeals court ruled that she could face civil penalties.

Paul Charlton, a former U.S. attorney in Arizona who made the decision to not charge Elliott criminally, said that prosecutors might have weighed similar issues when considering the charges against the Malboeufs.

Republic reporter Robert Anglen contributed to this article.