Wildfires threatening giant sequoias continue to grow with another red-flag warning day

Critical fire weather conditions are expected to persist through Sunday evening in Sequoia National Park, where hundreds of additional firefighters are now fighting a lightning-sparked wildfire that has reached the Giant Forest, home to many of the planet’s tallest and longest-living trees.

More than 600 firefighting personnel are now assigned to the KNP Complex fire, including 21 crews, 21 engines and eight helicopters. The fire, which swelled after the Colony and the Paradise fires merged on Friday, has grown to 21,777 acres as of Sunday morning and remains 0% contained.

A red-flag warning issued by the National Weather Service will continue until 8 p.m. Sunday, officials said. As a trough of low pressure moved in from the west Saturday evening, forecasters cautioned a confluence of factors — very low relative humidity levels and strong winds gusting as high as 45 mph — could lead to extreme fire behavior.

A separate lightning-sparked blaze dubbed the Windy fire — burning on the Tule River Reservation and the adjoining Sequoia National Forest and Giant Sequoia National Monument — has grown to 21,598 acres and is 3% contained. More than 700 personnel are fighting this fire, officials said, and another active day is expected.

When the Colony and Paradise fires merged into the KNP Complex fire, the blaze by Friday had swiftly marched through the westernmost tip of the Giant Forest near the Four Guardsmen, a grouping of giant sequoias that marks the forest’s entrance. Crews had been working for the past week to prepare the ancient sequoias by wrapping them — including General Sherman, considered the largest tree in the world by volume — in aluminum-foil-like material and raking vegetation from around their bases.

Then the wind picked up and a smoke inversion lifted, allowing the sun to heat up the vegetation, said Steven Bekkerus, public information officer with the Southern Area Blue Team.

“We actually had to pull our crews out for safety reasons,” he said.

Crews were able to get into the area later Saturday, after they cleared General’s Highway — the only way in and out of the forest — of falling rocks and flaming vegetation that had rolled onto the road.

Fire officials had 416 personnel assigned to the fire by Saturday evening, with more resources that arrived by Sunday morning.

“This is one of the highest priority fires in the country right now," Bekkerus said, "so we are trying to wrap those resources up and get what we need."

This story originally appeared in Los Angeles Times.