Updated at 1:30 p.m. EDT.
A wildfire in southwest Idaho has grown rapidly this week, burning more than 256,000 acres of sage grouse habitat and causing a "tragic impact" on local ranching communities, according to federal responders.
Since it ignited Monday, the Soda Fire has burned roughly 265,000 acres of Bureau of Land Management rangelands southwest of Boise, covering an area at least 40 miles long and 10 miles wide, according to the most recent report from InciWeb, an interagency service.
It is by far the largest wildfire currently burning in the United States, according to the National Interagency Fire Center in Boise.
Flames have been driven by gusty winds and hot, dry weather, and are being fueled by invasive cheat grass, according to Ron Dunton, BLM’s assistant director of fire and aviation.
"It absolutely blew out on us," Dunton said this morning.
Videos posted by Owhee County Sheriff’s Reserve Deputy Vern Tunnell show the flames jumping across Highway 95.
As of noon Eastern time, the fire had torched 202,193 acres of sage grouse habitat, Dunton said. It had also burned 53,000 acres of what BLM considers priority sage grouse habitat.
Wildfire and invasive species are the top threats facing grouse in the Great Basin. And wildfires are one of the key threats the Fish and Wildlife Service will look at next month when it decides whether grouse warrant protections under the Endangered Species Act.
Jack Connelly, a sage grouse expert who formerly worked for Idaho’s Department of Fish and Game, said he recently discussed the fire’s habitat impacts with the head of Idaho’s Office of Species Conservation.
"Everyone seems very concerned," he said. "At this point, loss of any more priority sage-grouse habitat is a very serious matter."
As of this morning, the fire was about 11 percent contained. There are 402 fire personnel on scene, with 18 engines, four helicopters and 20 bulldozers to build fire lines, Dunton said.
The fire offers a key test for an Interior Department strategy unveiled in January that asks wildland firefighters to prioritize the protection of grouse habitat after the protection of life and property.
Dunton said rangeland fires such as Soda typically do not last long. The blaze has burned down to lower elevations that are more accessible to heavy machinery, he said.
The area today is expected to remain dry with up to 30 mph wind gusts, which Dunton characterized as "semi-manageable."
"Fire behavior will continue to be very active as a cold front begins to [move] overhead, [bringing] a change in wind direction," InciWeb reported.
Over the past two days, the fire exhibited "extreme" behavior, causing the evacuation of four neighborhood roads near Homedale, Idaho, according to InciWeb. There were no evacuations currently in place this morning.
Bulldozers and air tankers were dispatched to protect grouse and grazing lands, it said.
"Over the course of the past several days, this fire has made a tragic impact to the local ranching community," InciWeb said. "We are working closely with those affected as we plan for emergency stabilization and rehabilitation both immediately and into the long term."
The fire has also forced Idaho high school sports coaches to consider postponing practices to avoid exposure to the smoke, USA Today reported.
Dunton said wildfire threats are expected to intensify over the weekend in the northern Rocky Mountains in Idaho and western Montana, where wind gusts may reach 60 mph.
"We can’t fight fires in that kind of wind," he said.
Federal and state fire officials yesterday morning raised the national preparedness level to its peak of 5 for the first time in two years as a result of expanding wildfire activity, a major commitment of fire resources and the likelihood that severe wildfire conditions will persist in the coming days.
As of yesterday, 39,609 wildfires had burned nearly 6.5 million acres, according to NIFC. The number of fires is about 80 percent of average at this time of year over the past decade. But the total number of acres is about 38 percent higher than normal, NIFC said.
Also as of yesterday, the Forest Service had spent $671 million of its $1 billion wildfire suppression budget. The Interior Department has spent $192 million of its $292 million suppression account.