A year after the Two Bulls Fire raged near Bend, the human-caused wildfire remains under investigation.

While investigators have talked to dozens of people about the blaze, the investigation still requires “significant follow-up,” said Jeff Bonebrake, investigation and cost-recovery coordinator for the Oregon Department of Forestry in Salem. At least nine or 10 investigators from the agency, the U.S. Forest Service and the Oregon State Police have worked to determine the cause and person or people responsible for the fire.

“It wouldn’t surprise me if we were at least a year out,” he said on Thursday.

The Two Bulls Fire started as a pair of separate fires burning near each other close to Bull Springs, west of Bend. The lookout on Black Butte spotted smoke from the fires around 12:45 p.m., June 7 — a year ago today. The fires went on to merge and burn 6,908 acres, or nearly 11 square miles, of mainly private timberland. Most of the spread was in the first day of the fire, causing the evacuation of about 254 homes and around 635 people on the west side of Bend.

The fast-moving fire close to the city brought comparisons to the Awbrey Hall Fire, which burned 3,350 acres, or nearly 5 square miles, and destroyed 22 homes in 1990.

Four days after the Two Bulls Fire started, Deschutes County Sheriff Larry Blanton put out a news release saying the fire, as well as a small fire along Skyliners Road on June 10, appeared to be arson, or illegal burning.

“The fires are suspicious in nature and the ongoing investigation indicates suspicion of potential arson,” he said in the June 11 release.

In the days following the start of the Two Bulls Fire a reward fund for information leading to arrest and conviction of the person or people responsible for the fire formed and grew quickly. The reward eventually reached more than $40,000.

The reward money may still be available, said Capt. Scott Beard of the Deschutes County Sheriff’s Office.

“If someone were to come forward right now, we would contact those donors and see if they are still willing to do that,” he said. Donors range from individuals to businesses to the Sheriff’s Office itself.

The Department of Forestry has not concluded that the Two Bulls Fire was arson, Bonebrake said. But based on the circumstances of two fires starting near each other close to the same time, he said it cannot be ruled out.

“That is a fairly significant coincidence,” he said. The fire does appear to have been human-caused, although he would not go into specifics of how because he doesn’t want to jeopardize the ongoing investigation.

Other fire investigations in Central Oregon have remained open for years. The “classic example” that quickly came to mind for Joe Stutler, a senior adviser for Deschutes County and former county forester, was the Awbrey Hall Fire.

Six years after the Awbrey Hall Fire, the Central Oregon Arson Task Force arrested Aaron Douglas Groshong on suspicion of starting that fire and seven other blazes. Groshong, a Bend man who was a firefighter and owned Wildcat Firefighting Service, was convicted of starting one of the other fires and wound up serving a year and a half in prison before being released and on parole for another three years. Groshong was never convicted of starting the Awbrey Hall Fire.

Investigators may quickly determine how a human-caused fire started, Stutler said, “but not who did it.”

The potential criminal implications of arson are part of why the investigation into the cause of the Two Bulls Fire is moving at the pace it is, Bonebrake said. Other factors include investigators being diverted to other blazes last year during a busy fire season around Oregon and the restitution aspects of a human-caused fire.

“We are trying to be very, very thorough on this because it is a very serious fire,” Bonebrake said.

Someone who intentionally or negligently starts a wildfire may be held accountable for the cost of fighting the fire, said Tracy Wrolson, district business manager for the Department of Forestry in Prineville. The agency led the fight of the Two Bulls Fire, which was contained on June 14 after eight days of firefighting.

While some accounting has yet to be completed, he said the cost of the fire looks to be about $5.4 million.

“Two Bulls was one of the largest ones for us in Central Oregon,” he said.

— Reporter: 541-617-7812, ddarling@bendbulletin.com