On August 19, a wildfire in northern California’s Stanislaus National Forest jumped Highway 120, a major thoroughfare leading to Yosemite National Park. The Rim Fire, as officials called it, had burned 800 acres of forest, and in the hot, dry weather of the late summer, seemed to be gaining momentum.
Ten days later, firefighters have roughly a third of the Rim Fire contained. But in the mean time, the inferno has consumed nearly 200,000 acres–over 300 square miles–on its way to becoming the 6th largest wildfire in California history. In two separate 24-hour spans, the fire burned through, respectively, 30,000 and 50,00 acres, has charred more than 40,000 acres of Yosemite National Park and threatened the Hetch Hetchy Reservior, which provides water and electricity to San Francisco. Watch an incredible time lapse video of the blaze (above).
“It’s a difficult fire,” Cal Fire Captain Mike Mohler told TIME as 4,000 firefighters worked on the ground to contain the blaze. Wood and brush–what firefighters call “fuel”–was critically dry; steep, rocky terrain made it hard for crews to reach important areas; and shifting wind patterns caused the fire to spread in unpredictable ways. “All of that in combination makes for a difficult fire to fight,” Mohler says.
Two weeks after the Rim Fire ignited, firefighters have the blaze about 30 percent contained. Backfires, small fires lit by crews to consume fuel and direct the main fire away from population centers, have succeeded in slowing the inferno, and cooler temperatures and higher humidity have fire officials optimistic, but they predict it will take two more weeks before the fire is fully contained.
After the Rim Fire is extinguished California faces more challenges. They’ve already burned through $44 million of their $172 million fire budget for the entire year.