Yosemite Wildfire Burns 149,000 Acres

An area the size of Chicago

Yosemite National Park, California (CNN) -- A massive northern California wildfire that's threatening Yosemite National Park and San Francisco's key water and power sources grew Monday, becoming the 13th largest in state history, state fire authorities said.

The Rim Fire, which has devoured more than 149,000 acres, has scorched an area about the size of the city of Chicago while more than 3,600 firefighters try to rein it in.

Susan Loesch and Curtis Evans just started settling into their second home in California's Sierra foothills a few months ago. Now, they're worried it could go up in smoke as the massive wildfire spreads.