What started the Glass fire? Cal Fire investigators focus on origin point

HOWELL MOUNTAIN — A trail of crime scene tape tied to trees leads up a narrow, winding road through a scorched oak forest and hillside vineyards toward a remote area under investigation as the origin of the massive Glass fire, the 5-day-old wildfire burning out of control in Napa and Sonoma counties.

Investigators appeared to have focused on a rural, gated property where the fire broke out at 3:48 a.m. Sunday morning on the slopes of Howell Mountain along North Fork Crystal Springs Road, located in the hills that ring the eastern side of Napa Valley, according to neighbors and workers in the area.

Cal Fire investigators will conduct separate probes into two ignition sites on the western side of Napa Valley, where fire erupted 15 hours later and spread west over Spring Mountain into Sonoma County and east Santa Rosa neighborhoods.

Fire officials have presumed those fires — initially called the Shady and Boysen fires, reported at 6:55 p.m. and 7:20 p.m. Sunday — started with embers from the Glass fire blown over the valley floor by strong winds that rapidly fueled the fires’ growth.

While the three fires have merged into a single blaze, called the Glass fire, Cal Fire will investigate each fire’s cause separately and make no assumptions as to how they started, Division Chief Ben Nicholls said.

“Just because the fires took place during the same period of time, we want to make sure that it is indeed attached to the main cause of fire and not another source of ignition,” Nicholls said.

Officially, Cal Fire lists the 200 block of North Fork Crystal Springs Road as the origin of the Glass fire.

KTVU reported investigators were concentrating on a Howell Mountain property along the dead-end road that belongs to Cakebread Cellars, a Rutherford winery that sells cabernet sauvignon made with grapes from Howell Mountain for $215 a bottle. The winery is "cooperating with and providing information to Cal Fire," a Cakebread spokeswoman said in a statement to KTVU, the television station reported.

A private security guard stood at the gate to the property Thursday.

Cal Fire informed the winery that it is looking at a number of properties, including the Cakebread property, and has yet to conclude its investigation, winery spokeswoman Katie Griesbeck said in a statement to the Napa Valley Register. “This indicates to us that Cal Fire has not identified a particular origin or cause,” she said.

Cakebread did not respond to an email seeking comment Thursday evening.

Most of the large, disastrous blazes that have erupted in California in recent years have been caused by power lines and equipment run by PG&E, including the 2019 Kincade fire in Sonoma County, the 2018 Camp fire in Butte County and most of the fires that broke out in October 2017 that destroyed more than 5,300 homes in Sonoma County alone.

There is no indication yet that PG&E equipment was involved in the Glass fire. The utility “has no information indicating that the Glass fire ignition is attributable to its facilities,” PG&E spokeswoman Deanna Contreras said in an email.

With many of the fires linked to PG&E, the utility had filed an “electric incident report” related to the fire’s outbreak, as it did the day after the Kincade fire started, alerting the public and state regulators that a broken piece of equipment on a PG&E transmission tower was found near the fire’s origin.

The utility has filed no incident reports related to the Glass fire, Contreras said.

Working a forklift at a property near the intersection of North Fork Crystal Springs and Crystal Springs roads, Greg Bowen said he’s watched investigators move from one area to another over the last several days.

A lifelong Calistoga resident and estate manager for Reverie II vineyards, he said the neighborhood is full of rumors about how the fire started, but time will tell.

He and his team are working hard to harvest the grapes, processing 24 tons Wednesday and expect to get another 40 tons done by Thursday’s end, despite the heavy smoke.

“It’s a mess, year after year,” Bowen said. “I’ve never seen fires in the valley like this, and I’ve lived here my whole life.”

You can reach Staff Writer Julie Johnson at 707-521-5220 or julie.johnson@pressdemocrat.com. On Twitter @jjpressdem.