Ross Valley Firefighters Assist with San Geronimo Wildfire

San Geronimo, CA – One of Marin County’s largest redwood groves was charred by a wildfire Tuesday near San Geronimo, but Marin County Fire Department crews were aided by cool and foggy weather.

By 4:45 p.m., the fire in Roy’s Redwoods Open Space Preserve just east of Nicasio Valley Road was estimated at four acres and was 90 percent contained. At the height of the fire, temperatures in the area were in the mid-50s with wind gusts up to 19 mph. 

Fire Marshal Scott Alber said the fire appeared to be human-caused, although it’s too early to determine if it was accidental or intentional. A full investigation will follow.

A column of smoke was reported at 7:02 a.m. Tuesday just north of the San Geronimo Golf Course, about 1 mile northwest of Woodacre and about 8 ½ miles northwest of downtown San Rafael. Responding crews created a staging area in a nearby meadow and approached the center of the blaze from several angles. Cloud cover prevented air support, but the fire was 30 percent contained by 8:10 a.m., 50 percent contained by 10:10 a.m. and 70 percent contained at 12:45 p.m.

Battalion Chief Mike Giannini said the response included 85 fire personnel, six engines and four water tenders. Personnel from Cal Fire, the Marin County Open Space District, the U.S. National Park Service, the Ross Valley Fire Department, the Larkspur Fire Department, the Southern Marin Fire District and the Novato Fire District aided in the effort to suppress the fire.

Giannini said crews would be at the site all day to contain the fire, ensure that no hot spots flare up and begin the mop-up effort. The Marin County Open Space District enacted an immediate 48-hour closure of the preserve to support the Fire Department's efforts to contain and investigate the fire.

There were no structures in the area and no injuries reported.

“This fire spread quickly during a damp and humid morning,” Giannini said. “This exemplifies the potential for high fire activity as a result of the continuing drought.”

Roy’s Redwoods, managed by Marin County Open Space District, contains old-growth redwood trees that are among the largest in Marin. The 293-acre preserve is a few miles east of where 40 acres burned in June on Mount Barnabe inside Samuel P. Taylor State Park. It is also about nine miles northwest of Marin’s most famous redwood grove, Muir Woods National Monument.