A helicopter drops water to stop the Ferguson Fire from reaching homes in the Darrah community of unincorporated Mariposa County, Calif., Wednesday, July 25, 2018. [Photo: AP/Noah Berger]

River Martinez, 10, breaks camp at the Upper Pines Campground in Yosemite National Park, Calif., on Wednesday, July 25, 2018. Martinez's family, visiting from Los Angeles, had to cut their stay short as portions of Yosemite close today to allow crews to battle the Ferguson fire burning nearby. [Photo: AP/Noah Berger]

In this Monday, July 16, 2018, file photo, the Ferguson Fire burns along a ridgeline in unincorporated Mariposa County, Calif. Officials said Saturday, July 21, 2018, that the Ferguson fire is churning northward, sending up smoke that has been obscuring valley views in the park. [Photo: AP/Noah Berger]