Crews are working to contain a wildfire that broke out in the early morning hours of July 5 and ripped through more than 443,000 acres of sagebrush and grassland. The cause of the Martin Fire, which has grown to become the largest blaze in the United States, is unknown and is being investigated by the Humboldt County Sheriff’s Office and the Bureau of Land Management.

The fire started near Paradise Valley, a small town in Humboldt County about 40 miles from Winnemucca and 200 miles from Reno, but spread quickly amid dry weather, high wind and above-average fuels on the range. According to a spokesperson with the management team for the Martin Fire, there was 200 to 1000 percent more wildfire fuel on the range because of a wet winter followed by a dry winter this year that turned plants into slick fuel for the fire.

At times in the past few days, because of heat, wind and the fire’s path up hilly terrain, flames reached as high as 45 feet and the fire, at times, moved as much as 11 miles in an hour. Since then, crews have contained more than 35 percent of the fire. An update released by the Great Basin incident management team this morning said “resources continue to be mobilized to the Martin Fire from around the country and firefighters are starting to turn the corner on the fire.”

The Bureau of Land Management, the federal agency that manages most of the land where the fire is burning, is looking at the impacts of the fire on the range and wildlife. The fire will likely have a lasting impact on grazing activities and could be a setback in sustaining habitat for sage grouse. Federal regulators have been working with Western states on a conservation framework to boost dwindling populations of the unique bird and avoid listing it as an endangered species.