Kings Canyon National Park reopened to visitors on Wednesday and Yosemite National Park will welcome back visitors on Friday as air quality improves.
Both parks closed last Thursday when smoke from the sixth-largest wildfire in recorded California history created hazardous air quality.
Park officials said air quality is projected to be in the moderate to unhealthy range for sensitive groups over the next few days.
Yosemite will reopen visitor services in stages throughout the weekend and portions of the park may intermittently close if smoke affects the air quality, park spokeswoman Jamie Richards said.
The Creek Fire, burning in the Sierra National Forest since Sept. 4, has devoured 452 square miles (1172 square kilometers) and destroyed 855 structures, according to the California Department of Forestry and Fire Protection. It is 32% contained.
Devils Postpile National Monument in the Sierra Nevada remains closed because of that fire, Denise Adamic of the National Park Service said.
Sequoia National Park, immediately to the south of Kings Canyon, remains closed. The park is threatened by the SQF Complex of fires ignited by lightning in the Sequoia National Forest.
Burning since Aug. 19, the complex has scorched more than 225 square miles (585 square kilometers) of forest and was 33% contained Wednesday. The fire has destroyed 191 structures and threatens nearly 3,200 others.
Some other national parks in California remain partially closed, with visitors barred from trails or sections of the parks. They include Pinnacles National Park in central California and Point Reyes National Seashore in Northern California, Adamic said.
In many parks that are open to visitors, restrooms, visitor centers and other buildings remain closed because of the coronavirus pandemic.
A previous version of this story incorrectly stated that the SQF Complex of fires started in the Sierra National Forest.