Smoke filled the sky and ash rained down across Los Angeles from a destructive wildfire that the mayor said was the largest in city's history.
It was one of several blazes that sent thousands fleeing homes across the US West during a blistering holiday weekend heatwave.
In Oregon, crews rescued about 140 hikers forced to spend the night in the woods after fire broke out along the popular Columbia River Gorge Trail.
Search and rescue crews air-dropped supplies as flames prevented the hikers' escape.
Wildfires also burned in a 2,700-year-old grove of giant sequoia trees near Yosemite National Park, forced evacuations in Glacier National Park and drove people from homes in parts of the West struggling with blazing temperatures.
Los Angeles Mayor Eric Garcetti declared a local emergency and at the state level, Governor Jerry Brown did the same for the county after the wildfire destroyed three homes and threatened hillside neighbourhoods.
More than a thousand firefighters fought flames that destroyed more than nine square miles of brush-covered mountains as authorities issued evacuation orders for homes in Los Angeles, Burbank and Glendale.
In Washington state, Governor Jay Inslee proclaimed a state of emergency across all counties as three major fires closed recreation areas and prompted evacuations.
Flames in Montana's Glacier National Park prompted officials to evacuate all residents, campers and tourists from one of the most popular areas of the park.
The order affects the Lake McDonald area, the western side of the dizzying Going-to-the Sun Road and some of the most visited trails in the area. The Lake McDonald Lodge, built in 1913, closed last week because of heavy smoke in the area.
