HESPERIA — After four major fires in the San Bernardino Mountains, Cajon Pass and Summit Valley area in the past month, a fire official said Thursday there is cause for concern and the amount is suspicious.

San Bernardino County Fire Department spokeswoman Tracey Martinez said the department is working with the San Bernardino National Forest Service, Cal Fire and the Sheriff’s Department in investigating the recent Pilot, Bluecut, Ken and Spring fires. She confirmed the Pilot Fire was not started by arson.

“We do have arson investigators and task forces that are made from all fire agencies on these cases,” Martinez said. “When you have so many fires breaking out in such close proximity and it’s consecutive it does cause a concern and is suspicious.”

The Spring Fire, which erupted on Wednesday afternoon in south Hesperia, was the latest in the series of fires to hit the area. The Pilot, Bluecut and Ken fires burned more than 45,000 acres over the last month, authorities said. The BlueCut Fire began Aug. 16 and scorched more than 36,000 acres in the region, prompting evacuation orders for more than 82,000 residents and destroying an estimated 110 homes, 216 outbuildings and more than 200 vehicles.

The Spring Fire was reported a little before 5 p.m. Wednesday by Hesperia resident Vernette Hansen, who lives off Highway 173, and it quickly spread to more than 30 acres in a little over an hour. It grew to about 50 acres before firefighters got a handle on it.

Hansen claims her husband came across a man driving in a white “newer model” pickup truck on Las Flores Ranch Road who said he was “driving back from LAX.”

“My husband thought that was strange. Then the guy said, 'There's a fire over there, must be a controlled burn,” Hansen told the Daily Press.

Hansen said her husband reported the truck’s license plate number to authorities.

“It's very odd for a nice vehicle to be coming off of that road. That road is pretty rough along most of it, and unless they work at the ranch or are on a heavy duty four-wheel drive or dirt bike, I can't imagine what he'd be doing in that area,” she said.

“Pure speculation on my part, but after you've been through three fires, you start to get a little paranoid. It concerned us enough that we felt the need to report it to the State Parks Ranger.”

Messages left with the Silverwood Lake State Recreation Area on Thursday about the Hansen's report were not immediately returned.

County Fire spokesman Jeff Allen said “nothing is confirmed” and “everything at this point is speculation.”

The Spring Fire began just days after authorities announced they had arrested a convicted arsonist on parole in the Cajon Pass for allegedly possessing flammable materials that "appeared to be set ready for immediate use" near a patch of land unscathed by the Bluecut Fire.

Authorities said Larry Missirilian, 61, of Ontario, was arrested on suspicion of arson and violation of his parole terms and he was booked without incident at West Valley Detention Center in Rancho Cucamonga.

However, booking records do not yield any bookings for Missirilian, who was allegedly found in a parked vehicle trespassing on Union Pacific Railroad property north of Cajon Boulevard and Cleghorn Road on Sept. 3. He was parked roughly 10 feet from "a large, dry unburned area where the BlueCut Fire had not burned," authorities said.

"They conducted a vehicle search and discovered Missirilian had a 5-gallon can of gasoline, large butane torches, lighter fluid, and new cigarette lighters underneath the driver's seat," sheriff's officials said. "The items appeared to be set ready for immediate use."

Missirilian was arrested roughly 12 hours before the Ken Fire burned 20 acres near Kenwood Avenue. Sheriff's officials did not suggest a connection between Missirilian and the start of the two earlier fires.

The cause of all the fires remains under investigation and anyone with information can call 1-800-47-ARSON. Those wishing to remain anonymous may call the WeTip hotline at 800-782-7436 or visit www.wetip.com.

Jose Quintero may be reached at 760-955-5332 or JQuintero@DesertDispatch.com. Follow him on Twitter at @DD_JQuintero.