YOSEMITE WEST — When a wall of flames raced up the hillside at Avalanche Creek on a recent afternoon, firefighters in Yosemite National Park had to act quickly.
The giant Ferguson Fire was headed toward the south rim of Yosemite Valley, and if
YOSEMITE WEST — When a wall of flames raced up the hillside at Avalanche Creek on a recent afternoon, firefighters in Yosemite National Park had to act quickly.
The giant Ferguson Fire was headed toward the south rim of Yosemite Valley, and if crews didn’t stop it here, the fire would open up on the edge of the park’s most beloved spot. Already, 10,000 acres of Yosemite had been charred, and much of the park was entering its third week of closure.
But just as the blaze began spitting hot embers out of the creek drainage and across Glacier Point Road, where helicopters with water buckets and engine teams with chain saws had staked their line of defense, firefighters caught a break — at least for the moment.
The fire struck a patch of forest that had burned in a previous fire. With fewer trees and less brush to serve as fuel, the flames began to taper off. The conflagration slowed, a pause that crews hoped would become a turning point in the firefight and one that forestry experts say highlights the benefits of having a regular regime of fire on the landscape.
“When these fires push into old burns, there’s progress,” said Kelly Martin, chief of fire and aviation management at Yosemite, who has been helping oversee the 96,000-acre Ferguson Fire. “It’s basically fighting fire with fire.”
As California grasps at ways to prevent the increasingly intense blazes seen in recent years, the idea of letting fire burn in the state’s wildlands, instead of trying to prevent it, is gaining currency.
Experts say allowing natural fire to run its course or setting controlled burns, when people and property aren’t threatened, will reduce hazardous vegetation and make future wildfires far less catastrophic. One of the main reasons the situation has gotten so bad, experts say, is that decades of fire suppression have broken the cycle of fire that’s inherent to forests, creating an unnatural buildup of tinder.
As much as 50 percent of the land consumed by the Ferguson Fire hasn’t burned since record-keeping began in the 1930s, according to the U.S. Forest Service. Historically, conifer forests in the Sierra burned as often as every 10 years.
While federal and state land managers have long dabbled in planned fire, they have yet to fully embrace it, even as last year’s devastation in the Wine Country and this summer’s deadly inferno in Redding are hastening the call for change.
When the Ferguson Fire ignited just west of Yosemite in the Sierra National Forest on July 13, Forest Service officials made the call to aggressively attack it. The towns of El Portal and Mariposa were nearby, as was the national park with its glacial canyons and towering waterfalls, and 4 million annual tourists.
“There were no questions asked,” said District Ranger Denise Tolmie. “It’s a full-suppression fire.”
But about 30 miles to the east, where another blaze is burning, the same Forest Service officials made a different decision, one that suggests at least an emerging interest in new tactics.
When Tolmie got the report of the lightning-ignited fire near the headwaters of the San Joaquin River on June 11, she decided not to send a strike team to stop it. The Lions Fire was burning a comfortable distance from roads and communities, so she would let it go.
“We felt the fire effects would be positive,” Tolmie said.
Tolmie said she’d like to see more of the ecosystem and fuel-reduc