The latest of 23 active wildfires in California has burnt through more than 4,000 acres of brush and grass in Cleveland National Forest, authorities said.
Named after the Holy Jim Canyon, where the fire was first sparked, the Holy Fire saw 10 helicopters and 5 air tankers supporting firefighters on the ground.
Video taken by Vanessa Kuo on American Air 382 showed a giant cloud of smoke billowing close to the airplane's altitude.
The fire broke out at 1.30pm local time (2030 GMT) on Monday, August 6, and continued to burn into the night.
Northern California is enduring temperatures that could reach 110 degrees Fahrenheit (43 Celsisu) and winds of up to 15 mph (24 kph) - conditions that have allowed the massive, out-of-control Mendocino Complex Fire to become the biggest in California's history.