California’s Rim Fire now almost 180,000 acres in size

The California Rim Fire that threatens homes in the Californian northern mountains has grown to be nearly 180,000 acres.

The Rim Fire has already reached parts of the Yosemite National Park and continues to grow by day, USA Today reports. The fire has swelled an additional 20,000 acres in size since Monday.

The 11-day-old fire has burned two dozen structures and 4,500 more remain in its path. The Rim Fire is the largest wildfire on record in the Sierra Nevada Mountains. Though it has hit parts of Yosemite, it has mostly affected backcountry, allowing the park to remain largely open.

Wednesday’s weather conditions might bring challenges to the more than 3,700 firefighters battling the blaze as the heavy smoke is expected to stay low to the ground, making it difficult to see.

The Los Angeles Times reports that though the fire has spread to the Hetch Hetchy Watershed, the San Francisco water supply remains unaffected.

The spokesman for the San Francisco Public Utilities Commission, Tyrone Jue, acknowledged that ash from the fire has been seen on a key reservoir, but water quality remains fine.