Mt. Diablo fire grows to 3,700 acres as erratic winds fan flames

A fast-moving Bay Area brush fire raging out of control in and around Mt. Diablo State Park had charred at least 3,700 acres, fire officials said Monday evening.

The Morgan fire was 20% contained but more than doubled in size during the day as firefighters on the ground struggled with hot weather and erratic winds that were pushing flames across dry brush, the California Department of Forestry and Fire Protection said.

“It’s been another really hot day,” Cal Fire Staff Chief David Shew told The Times. “It’s bone dry out there.”

Temperatures were in the 90s to around 100, according to the National Weather Service.

Shew said fire crews were making good progress but that two huge DC 10 tankers dropping fire retardant on the flames had to be diverted to another blaze that broke out Monday afternoon in Shasta County. That fire had scorched about 1,500 acres.

Two other air tankers and three water-dropping helicopters remained at the Morgan fire and made repeated assaults while about 700 firefighters battled to contain the blaze on the ground, Cal Fire said.

Earlier Monday, the blaze was threatening PG&E transmission lines and about 100 residences, fire officials said. The 3,849-foot summit is a popular destination for hikers and bikers and on clear days can offer spectacular views of San Francisco Bay.

The fire broke out Sunday afternoon and raged on the northeast side of Mt. Diablo before spreading to the south and southeast sides of the mountain, Cal Fire said. The blaze started near Morgan Territory Road southeast of Clayton in Contra Costa County.

Evacuations were ordered for Oak Hill Lane, Curry Canyon and Curry Point. Earlier Monday, only a few residents had trickled into a shelter set up at Clayton Community Library in Clayton, but it was ordered to remain open for two more nights, said Jim Mallory, a Red Cross spokesman at the site.

“We’re just in a kind of standby mode,” he said.

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robert.lopez@latimes.com