The weekend’s intense heat wave coincided with a fire on Mount Vision that gave responders a chance to gear up while fire fuels are at their peak moisture after winter’s heavy rains.
On Monday afternoon, a branch fell on a power line on Mount Vision Road in the Point Reyes National Seashore, sparking a blaze that drew more than 100 responders and blocked several roads.
Although Pacific Gas & Electric turned off power in parts of six Northern California counties over the weekend to reduce wildfire risk, Marin was spared any planned outage despite a red flag warning issued by the National Weather Service.
In Inverness, temperatures reached 100 degrees Fahrenheit on Monday. Down the driveway to a park ranger residence just over a mile up Mount Vision Road from Sir Francis Drake Boulevard, a tree limb fell onto a power line, igniting what became a 2.2-acre fire that burned through green grasses, salal and huckleberry bushes.
Reports of the blaze, dubbed the Drake Fire, were first called in at 2:30 p.m. Employees and volunteers from the Inverness Volunteer and Marin County Fire Departments, the National Park Service, the Marin County Sheriff’s Office and Cal Fire responded, finding the blaze slowly spreading about 25 feet from a vacant residence.
Although fire fuels were still wet from the winter’s heavy rains, there were two challenges to containing the fire: the location was remote, and creating a perimeter required clearing a lot of vegetation, according to Bret McTigue, a Marin County Fire battalion chief. Sensitive to the national park, firefighters did not use bulldozers to clear fuels around the flames and minimally dropped flame-retardant to protect the house, which park spokeswoman Jennifer Stock said had been empty for at least a year.
“Air support was instrumental because of the location,” Chief McTigue said. “Had they not made that drop, the structure would’ve been threatened.” The Cal Fire helicopter collected water from local ponds to douse the fire for three hours.
At 6 p.m., Marin County Fire announced that the forward progress of the blaze had stopped, though crews cleaned up through the night.
The park service closed Sir Francis Drake Boulevard past Vision Road while the fire was being contained, creating a traffic jam and blocking people from returning home.
Residents were confused when Marin County Fire posted on Facebook and Twitter that “units are responding to a fire along Inverness Road near Limantour.” The fire was several miles north of the Limantour area, and Inverness Road doesn’t exist. “This made us all think there was another fire,” said Sue Van der Wal, who lives on Vision Road along the route crews took to the fire.
Firefighters had to take Vision Road to access the blaze because Mount Vision Road, which would have taken slightly less time, collapsed during heavy storms in February. If Mount Vision Road was passable, resources might have travelled that way, Chief McTigue said, “but it wasn’t a factor in containment.” Repairs on the road will be complete by August, Ms. Stock said.
The day after the fire, PG&E workers repaired damaged equipment in the burn zone. The company follows vegetation clearance requirements, which requires four feet of space around power lines, according to spokesperson Deanna Contreras. “In response to the growing risk of wildfire in our state, we’ve enhanced our vegetation management, so we are clearing from conductor to sky,” she said.
The Drake Fire wasn’t the area’s only fire involving PG&E equipment during the heat wave. The day before, on Sunday, a PG&E transformer started a quarter-acre brush fire near Mount Tamalpais that was extinguished in half an hour.
An interagency report on the fire outlook for 2019 predicted that fire fuels at lower elevations in Northern California would reach peak moisture in early June and that the winter’s heavy rains would lead to robust brush growth and above-normal fire risk through October.