For the first time since the blaze broke out in a neighboring forest two weeks ago, smoke obscured Yosemite Valley, home to the park's most popular landmarks, spokeswoman Kari Cobb said.
"I'm in Yosemite Valley right now, and I cannot see the cliffs around me," Cobb said. "The wind has shifted and smoke is impacting the entire park. We have been lucky until now."
All the campgrounds in the Valley still were full as of Saturday morning, despite the thick blanket and burning smell that permeated the area, she said.
Meanwhile, firefighting aircraft remained grounded because of low visibility caused by the smoke, U.S. Forest Service spokesman Mark Healey said. The blaze had scorched 343 square miles of brush, oaks and pines and 11 homes, as of Saturday.
Of that total, 94 square miles of wilderness have burned in the northern section of Yosemite, up from 75 square miles a day earlier.
Although containment efforts proceeded on a positive note overnight, officials were concerned Saturday about a 150-acre spot fire that crossed a road and prompted an evacuation order for homes near the west entrance of Yosemite, Healey said.
"The weather is keeping the smoke on the ground, so we can't use aerial suppression efforts at this time," he said.
Healey said fresh firefighters were being brought in to replace tired crews, but that officials did not plan to reduce the nearly 5,000 people assigned to the fire.
The blaze's cause is under investigation.