Officials say a massive wildfire burning near Yosemite National Park grew overnight, but they are still making progress in containing it.


Trees burned by the Rim Fire stand in Yosemite National Park (Justin Sullivan/Getty Images)

The Rim Fire remained 20 percent contained on Tuesday morning. Officials said the fire grew to about 280 square miles, up from about 252 square miles the previous day, but back burning by crews was responsible for at least part of that increase.

California fire spokesman Daniel Berlant said crews are anticipating cooler temperatures and higher humidity this week that could allow them to gain the upper hand.

The fire is threatening thousands of structures, the main reservoir serving San Francisco and historic giant sequoias.

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