Firefighters prepare to defend historic Boole Tree, other giant sequoias from Rough fire

The voracious Rough fire has turned back toward occupied areas and national monuments, prompting new evacuations Thursday and a mad dash to protect the world-famous giant sequoia trees in Kings Canyon National Park and Sequoia National Forest.

The blaze, now more than 110,000 acres, is bearing down on the tallest trees on the planet. Although the historic trees, many of which are thousands of years old, are naturally resistant to wildfires, firefighters aren’t taking any chances.

Rough fire public information officer Andy Isolano said the Converse Basin, home to a grove of around 60 giant sequoia trees, is now in the active fire area. It’s hard for the nearly 2,200 firefighters to know exactly where the flames are at all times, Isolano said, so they rely on maps provided each morning after planes fly overhead each night. The fire is expected to spread to the basin within 24 hours, but weather and other factors could alter its course.

The Converse Basin is home to the Boole Tree – the world’s sixth-largest tree and the largest on U.S. Forest Service land.

According to the Forest Service, the 268.8-foot-tall tree is believed to be over 2,000 years old. It was named around 1895 after Franklin A. Boole, a logger who felled most of the grove but spared the tree because of its massive size. It was believed to be the largest tree on Earth until 1931.

“It’s not like you can put a blanket over it,” Isolano said about the Boole, which is 113 feet in circumference. “And those old trees have been through fires before.

“But this is a national monument. It can’t be replaced. So we are being extra, extra careful.”

The giant sequoias can be at risk if nearby trees and other flammable materials cause the fire to grow large enough to crown, or burn the tops, of the sequoias. If the flames reach that height, they can kill the trees and pose a significant threat to the surrounding area.

Fire crews have cut containment lines around the massive tree, and firefighters stand guard, ready to battle any oncoming flames.

This extra care includes installing a dozen sprinklers around the Boole. The sprinklers are manually operated, Isolano said. Firefighters are using them to wet the tree in anticipation of the fire, as drought conditions have weakened it over the last few years. If flames bear down on the grove, firefighters will switch on the sprinklers – and leave them on – to try and help the tree’s natural defenses.

Mounting sprinklers around historic trees is a common practice during fires, Isolano said.

Firefighters also are bracing for a similar scenario in Grant Grove, where flames are starting to bear down on the General Grant Tree – the second-largest on Earth.

Isolano said the blaze is still about 4 miles from Grant Grove, which was evacuated Thursday, but crews have prepared a similar sprinkler system around the General Grant Tree and covered the area in flame retardant.

According to the Forest Service, this mighty tree, located in Kings Canyon National Park, was designated “The Nation’s Christmas Tree” by President Calvin Coolidge in 1926. People have flocked to the tree every year since.

The Sanger Chamber of Commerce sponsors the annual “Trek to the Tree” every second Sunday in December.

Although firefighters are taking every precaution possible, Isolano said that he isn’t too worried about the massive sequoias.

“The forest has probably burned like this in the last 500 years, and they’re still standing.”

This story was originally published September 10, 2015 at 7:21 PM with the headline "Firefighters prepare to defend historic Boole Tree, other giant sequoias from Rough fire."