(CBS News) TUOLUMNE, Calif. -- One of the biggest wildfires in California history got bigger Tuesday. Firefighters, and that is progress, but overnight, it grew by 30,000 acres to 180,000 acres in all. One-hundred-eleven structures have burned.
The flames pushed. By sunrise, the burn zone inside the park had doubled to 64 square miles. The main tourist areas remain unaffected, but the fire is erratic.
"When you get a fire that's this massive, and you start to get these different columns that are in different areas, the fire actually creates its own wind," said Michael Williams, who is on the Rim Fire command team. "So when you get this heated mass, this plume that's developing, when it actually settles back down on the fire, and what it does is it actually spreads the fire in a different direction."
The fire has reached the Hetch Hetchy Reservioir, which. Officials fear ash could get into the water, but so far, it has not been contaminated.
Crews soaked the ground to protect 2,000-year-old sequoias, but their biggest battle is still near mountain communities, where 4,500 homes are threatened.
Samantha Smith's home is at the base of the mountain known as Duck Wall Peak. She's been living at a Red Cross shelter since fleeing her home last week.
"If you were standing on my front porch, you'd be looking at the flames right now - if my front porch was still there," she said, adding she didn't know whether her home is still standing.
Watch: Firefighters set sprinklers on Sequoias to protect against wildfire, below.
Smith is seven months pregnant and had just assembled the baby's crib.
"We just got it set up, and he's only due in two months, so not knowing if I'll have his crib or any of the things that he need is hard," she said.
Officials have not said when residents may be able to check on their homes. The fire is the largest of more than a dozen fires straining resources in the West. Fire managers have contacted the Pentagon and even Canada about possible reinforcements.