The Railroad Fire south of Yosemite National Park was at 5,414 acres with 15 percent containment Saturday night, though ancient Giant Sequoias appear to be out of danger.
Fire officials said the western side of the fire, in and around Yosemite Mountain Sugar Pine Railroad, was largely controlled.
There were more than 800 firefighting personnel involved, with an expected containment date of Sept. 8.
Four helicopters, 58 fire engines and eight dozers also were tackling the blaze.
An advisory evacuation for the communities in the Sky Ranch area remains in effect. Highway 41 remains closed from south of Wawona to Cedar Valley Drive.
The cause of the fire remains unknown.