Investigations into the causes of the Jacksonville and Twist fires that blew up on consecutive days less than a mile of each other in July 2017 never determined the causes of either blaze, Cal Fire reports obtained through a public records request show.

Investigation reports completed July 31, 2017, and Feb. 26, 2018, and totaling 184 pages show while no definitive causes were nailed down, two different investigators assigned to the separate fires left open the possibility that each may have been started by a vehicle.

The Jacksonville and Twist fires broke out during a spell of triple-digit temperatures during the height of the 2017 fire season and burned more than 800 acres southeast of Jamestown.

The fast-moving Jacksonville Fire prompted rolling evacuations and aggressive aerial attacks as it burned 675 to 690 acres, northeast from Jacksonville Road across cured-dry grass ranchlands toward Algerine Road and Twist Road, on July 29.

The Twist Fire broke out July 30 next to Twist Road and burned quickly from grasslands into heavier fuels on Hog Mountain, prompting more aerial attacks, raising concerns among cattlemen, blackening 120 acres, and destroying a ranch home and property.

Luis Morado, a Cal Fire captain, law enforcement and fire prevention officer, did an 11-page report on the Jacksonville Fire, completed two days after the fire started. Morado noted that a pilot in an air attack spotter plane reported the fire was initially on the west side, the downhill side, of a rural stretch of Jacksonville Road, in the 15500 Jacksonville Road address area, south of the Sullivan Creek bridge.

Morado considered and dismissed as causes the possibilities of lightning, a campfire, debris burning, railroad activity, power lines, other equipment, and spontaneous combustion. Morado concluded he could not rule out the possibilities of arson, fireworks, vehicles, smoking and someone playing with fire.

Morado was near the scene of where the Jacksonville Fire started, on the day it started, and he interviewed three men, who walked up from Sullivan Creek below the fire. They said they had been at the creek for about an hour to cool off. It was 104 degrees when the Jacksonville Fire started about 2 p.m. that day.

One man said they had stopped at the first bridge and saw an adult male with a young female. He said the man told them about a shallow swimming area near a culvert pipe, so they hiked back up to their vehicle and moved near the culvert pipe, Morado said in his report. They were at the bottom swimming for about 10 minutes when they heard a boom. One man looked up and saw smoke, another said he saw smoke first and then heard an explosion. They then decided to hike back up to their vehicle. They hiked diagonally away from the fire until they met Morado. Morado asked them if they’d been smoking and they said no.

Two of the men also said there was a helicopter in the area and the helicopter may have backfired.

Morado also interviewed a woman whose mother lives in the area and saw a white-tan recreational vehicle on the side of a road before the fire. Boucher’s mother came back the same way and found a fire burning where the white-tan RV had been parked.

Morado interviewed the owner of the white-tan RV, who said he had moved his RV to plug into shore power. He said he also went to a gas station in Jamestown to add fuel to a generator tank, and he got a flat tire at the gas station. He was headed south on Jacksonville Road when he stopped on the side of the road because he’d seen a wallet and he thought he’d scored. But it turned out to be a blue piece of plastic trash.

Morado took photos of Johnson’s RV and spots where the RV may have dragged on concrete. He noted grass on the front of the vehicle’s grill. The undersides of the RV’s exhaust did not have fresh scrape marks on them.

Matthew Gilbert, a Cal Fire battalion chief for fire prevention, investigated the Twist Fire and completed a two-page report in February 2018. The fire was first reported in the area of 14750 Twist Road and Gilbert concluded the most probable specific origin area was adjacent to some mailboxes, near the address marker for 14555 Twist Road.

Based on burn indications and witness statements, in that scene the most probable cause was vehicle-related. There were scrape marks in the soil and vegetation, there was a rock with a pushed appearance, and there were two smaller rocks with fresh scrapes. The scrape marks were about 7 feet 6 inches from the edge of a gravel driveway. No information was developed on identification or ownership of the vehicle.

Asked in November 2017 why no details of the Jacksonville and Twist investigations could be released, Gilbert said Cal Fire didn’t want to release information that could jeopardize the investigations.

Gilbert emphasized at that point that no one with Cal Fire had publicly stated whether the causes of the Jacksonville Fire or the Twist Fire had been determined to be arson or accidental.

Asked why it’s so complicated, if investigators already know the causes and aren’t saying, and if the trail toward possible suspects had gone cold, Gilbert said, “In an ideal world there is information that is likely known only to someone who may have started a fire, and we wouldn’t want to compromise that by releasing details.”

The Union Democrat requested Cal Fire records of the Jacksonville and Twist investigations on Feb. 22, 2019. Cal Fire’s legal division mailed the investigation reports on DVD last week.

Contact Guy McCarthy at or 588-4585. Follow him on Twitter at @GuyMcCarthy.