A wildfire in Northern California continued its destructive march Monday toward a grove of old redwood trees in Yosemite National Park as the Washburn Fire expanded to more than 2,300 acres.
Using a four-foot-tall sprinkler system to fend off noxious flames and keep much-needed moisture in the air, firefighters worked to create a perimeter around about 500 mature redwoods in the park’s Mariposa Grove.
The Washburn Fire, on the western flank of the Sierra Nevada, was 25% under control Monday night. Nearby Wawona continued to be threatened as the region was scorched by high temperatures.
There are no reports of serious damage to named trees, including the 3,000-year-old Grizzly Giant.
“Right now the sprinklers are doing a lot of good,” said US Forest Service spokesman Stanley Bercovitz.
When asked if firefighters had made protecting certain trees a priority, Bercovitz replied simply, “That’s like asking who your favorite kid is.”
Mariposa Grove and Yosemite Valley have been protected since President Abraham Lincoln signed legislation in 1864. The forest has a long history of prescribed burning, which significantly reduces the negative effects of very severe fires, the National Park Service said in a statement.
Native to only about 70 groves scattered along the western slope of the Sierra Nevada, the giant sequoias were once considered impervious to flames, but they have become increasingly vulnerable as wildfires, fueled by a buildup of undergrowth after a century of firefighting and the effects of drought, exacerbated by climate change, have become more intense and destructive.
Lightning-caused wildfires in the past two years have killed up to a fifth of the estimated 75,000 large redwoods, which are a major draw for tourists.
“Fortunately, there have been no erratic winds that have influenced the fire behaviour,” says fire spokesman Marc Peebles. “We are dealing with the high pressure above the fire, which causes the temperature to rise. However, we do get a fair amount of humidity at night, which moderates the fire behavior, allowing our night shift firefighters to do a good job.”
The area in the southern part of Yosemite was closed to visitors, but the rest of the national park remained open.
A heat advisory was issued for the Central Valley stretching below the Sierra, while a high temperature of 88 degrees was predicted in the fire zone for the village of Wawona, where hundreds of tourists and residents had to evacuate Friday.
There was no apparent natural spark for the fire, which broke out next to the park’s Washburn Trail on Thursday. Visitors walking in the woods reported smoke.
A fierce windstorm ripped through the forest more than a year ago, knocking over 15 giant redwoods and countless other trees.
The fallen trees, along with huge numbers of pines killed by bark beetles, provided ample fuel for the flames.
So far this year, more than 35,000 wildfires in the U.S. have burned nearly 4.7 million acres, according to the National Interagency Fire Center, well above the average for both wildfires and acres burned.