Flames racing through rugged terrain in Northern California destroyed multiple homes Saturday as the state’s largest wildfire intensified and numerous other blazes battered the US West.

 The Dixie fire, which started July 14, had already levelled over a dozen houses and other structures when it tore through the tiny town of Indian Falls after dark. It was burning in a remote area with limited access, hampering firefighters’ efforts as it advanced eastward, fire officials said.

 The blaze has charred more than 181,000 acres (73,200 hectares) in Plumas and Butte counties and prompted evacuation orders in several small communities and along the west shore of Lake Almano, a popular getaway. The fire was 20% contained as of Saturday night.

Meanwhile, the nation’s largest wildfire, southern Oregon’s Bootleg fire, was nearly halfway surrounded Saturday as more than 2,200 crew members worked to corral it in the heat and wind, fire officials said. The growth of the sprawling blaze had slowed, but thousands of homes remained threatened on its eastern side, authorities said.

 “This fire is resistant to stopping at dozer lines,” Jim Hanson, fire behaviour analyst, said in a news release from the Oregon Department of Forestry. “With the critically dry weather and fuels we are experiencing, firefighters are having to constantly reevaluate their control lines and look for contingency options.”

 In California, Gov. Gavin Newsom has declared a state of emergency for four northern counties because of wildfires that he said were causing “conditions of extreme peril to the safety of persons and property.” The proclamation opened the way for more state support.

 Such conditions are often from a combination of unusual random, short-term and natural weather patterns heightened by long-term, human-caused climate change. Global warming has made the West much warmer and drier in the past 30 years.