A sign warning visitors to leave because of fire is seen at the Hospital Rock picnic area of the Sequoia National Park, in Tulare County, California, U.S. September 18, 2021.

Sequoia trunks are seen in the Sequoia National Forest in California, U.S. September 17, 2021.

Handcrews clear brush and undergrowth away from trees in the path of the fire, at Sequoia National Park, in Tulare County, California, U.S. September 18, 2021.

Fire information officer Mark Garrett looks up towards hillsides that burned in the KNP Complex fire near the Hospital Rock Picnic Area of the Sequoia National Park, in Tulare County, California, U.S. September 18, 2021.

Firefighters cover a sign at Sequoia National Park, California, U.S., in this picture obtained by Reuters on September 17, 2021. Sequoia and Kings Canyon National Park Service/Handout via REUTERS

A fire truck drives by a wooden sign wrapped in fire resistant aluminum to protect it from the KNP Complex fire, at the entrance of the Sequoia National Park, in Tulare County, California, U.S. September 18, 2021.

A firefighting helicopter drops water on hotspots burning in the KNP Complex fire, at Sequoia National Park in Tulare County, California, U.S. September 18, 2021.

A car drives out of the smoke from the KNP Complex fire, next to a sign announcing that the Sequoia National Park is closed, near Three Rivers, California, U.S. Spetember 17, 2021.

Sequoia trees are seen admist smokes in the Sequoia National Forest in California, U.S. September 17, 2021.

Smoke from a fire is seen through the trees of The Lost Grove in the Sequoia National Forest in California, U.S. September 17, 2021.

A wooden sign wrapped in fire resistant aluminum to protect it from the KNP Complex fire is seen at the entrance of the Sequoia National Park, in Tulare County, California, U.S. September 18, 2021.