Firefighters in California braced for another rough day Sunday in their efforts to gain ground on a wildfire that has burned its way into Yosemite National Park.

Strong winds, some of which could reach speeds of between 30 and 40 miles per hour, could push the raging fire further into the northwest edge of the park, threatening thousands of rural homes. More than 5,500 homes are already threatened and at least four have been destroyed.

Meanwhile, park officials are clearing brush and setting sprinklers to protect two groves of giant sequoias. The iconic trees can resist fire, but dry conditions and heavy brush are forcing extra precautions to be taken in the Tuolumne and Merced groves. About three dozen of the giant trees are affected.

“All of the plants and trees in Yosemite are important, but the giant sequoias are incredibly important both for what they are and as symbols of the National Park System,” park spokesman Scott Gediman told the Associated Press Saturday.