Rim Fire: 20-Percent Contained

Although the flames have been winning for the past 11 days now, firefighters are making some progress in the battle against the stubborn Rim Fire burning near Yosemite National Park.

So far, the fire is 20-percent contained.

More than 4,000 firefighters are on the front lines.

Ferocious flames have now consumed about 280 square miles of forest - that's nearly three times the size of Fresno.

But part of the recent growth can be blamed on firefighters setting back-burns.

"They're cutting line, they're using bull dozers to actually put a barrier between the fire and any structures or infrastructure that may be threatened," said Mike Mohler, Cal Fire Public Information Officer.

Half a dozen air tankers, 17 helicopters, 491 engines, 61 dozers, and 46 water tenders - it's cost the state more than $20 million so far.

Firefighters left to work and wonder - when will they finally be able to tame these flames?

"You start to run into fatigue and so we just have to make sure we're managing the firefighters' fatigue and managing our own fatigue and making sure we keep that work to rest ratio," said Mike Williams, Rim Fire information officer.

The fire has reached the Hetch Hetchy Reservoir, which is where San Francisco gets its drinking water.

But officials say falling ash has not yet contaminated the water supply.