Mosquito Fire: Firefighters halt wind-whipped wall of flames near Foresthill

FORESTHILL, Placer County -- Overnight the small army of firefighters battling the Mosquito Fire along the middle fork of the American River in Placer County were able to hold the line against a rapidly advancing wall of flames in the Todd Valley.

Operations Chief Don Fregulia said the firefight began on Tuesday afternoon. A spot fire jumped the middle fork and fueled by tinder-dry brush and gusty winds began making a run toward Foresthill.

"It was a spot fire that just took off," he said during his Wednesday morning briefing. "It jumped the river and it was two acres, then it was five acres, then it was 1,100 acres. It was very, very active fire behavior."

Crews had been building contingency lines south of Todd Valley and Foresthill along the El Dorado-Placer county line in preparation for just such a run and made their stand there.

"Fortunately, we were prepared for it in Foresthill," Fregulia said. "We had a good successful night shift last night. We were able to hold that fire south of the Foresthill community."

Mosquito Fire: Placer County evacuation map | El Dorado County evacuation map | Cal Fire incident page

But fire spokesperson Scott McLean said some buildings were lost to the advancing flames just south of the community. The exact number won't be known until damage assessment teams are able to canvas the area.

The blaze had grown to 58,544 acres -- nearly 91 square miles -- with 20% containment by Wednesday morning.

More than 11,000 people have been evacuated and nearly 6,000 structures are threatened — an increase in both figures as the blaze raged Tuesday near Foresthill and Todd Valley.

Increased winds Tuesday pushed out a smoke inversion layer that had been stifling the blaze and gave fresh oxygen to the flames.

"It's not that it's a wind-driven fire, but the southwest flow is going to allow more air to come in," Cal Fire fire behaviorist Jonathon Pengburn told the crews.

Pengburn said the geography of the region also played a role in Tuesday's spot fire.

"There are a lot of twists and turns in the river," he said. "What that does is channel the wind and sometimes it swirls and makes an eddy (vortex of wind)."

Elsewhere, the blaze was also advancing to the northwest in an area of forest untouched by either the King Fire (fall of 2014) or the American Fire (August 2013). 

"There is a lot of fuel between the fire scars," Pengburn said. "You have the King Fire and the American Fire, in-between you have an island where you have unburned (forest) with no fire history... Plenty to burn."

Damage assessment teams in the area of Michigan Bluff, Foresthill and Volcanoville have found at least 46 structures that have been consumed by flames. 

Along Michigan Bluff Road the flames destroyed at least a half dozen homes and damaged others.

"We watched it go from the river to the ridge over there in Volcano in about 20 minutes," said Johnny Worton. "The flames were gargantuan."

The cause of the blaze remains under investigation. Pacific Gas & Electric said unspecified "electrical activity" occurred close in time to the report of the fire on Tuesday.  

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