The Washburn fire in Yosemite National Park is continuing to threaten the Mariposa Grove, home to about 500 ancient sequoias, including Grizzly Giant.

Grizzly Giant is 200 feet tall and the second-largest tree in Yosemite. In 1864, President Abraham Lincoln signed legislation safeguarding the Mariposa Grove and Yosemite for “public use, resort, and recreation,” and the Los Angeles Times notes this was “the first time that the federal government set aside scenic natural areas to be protected for the benefit of future generations.”

The Washburn fire was first reported on Thursday afternoon near the Washburn Trail at the southern end of Yosemite National Park. So far, the blaze has scorched 1,591 acres, and is also threatening the community of Wawona. About 300 firefighters are on the scene, battling the fire from the ground and the air. Crews are also installing portable sprinkler systems in the Mariposa Grove, to spray tree and increase humidity. Officials are hopeful that recent controlled burns near the grove will slow the spread of fire in this area.

The conditions are hot and dry, which is tough on firefighters and “better for burning, unfortunately,” U.S. Forest Service spokesman Stanley Bercovitz told the Times. In a statement, fire officials said the fire is “burning in difficult terrain with continuous fuels,” and this is posing a “significant threat to firefighters.”

Last year, two wildfires sparked by lightning strikes destroyed 3,600 sequoias in Northern California. While these trees can handle low-intensity fires, and need them in order to reproduce, they cannot withstand more intense wildfires that are fueled by drought and climate change.