(CNN)  -- A wildfire continued its rampage through the San Bernardino National Forest in Southern California on Monday, but the U.S. Forest Service said fire crews were gaining ground. The Sheep Fire in Southern California has burned thousands of acres and left this bus a charred ruin. "Firefighters have made very good progress against the Sheep Fire. It's currently at approximately 7,500 acres with 20 percent containment," U.S. Forest Service spokeswoman Robin Prince said Monday. The fire, which was reported Saturday afternoon in the Lytle Creek area, quickly grew to 3,500 acres by early Sunday and forced about 4,000 people in the community of Wrightwood from their homes.
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Sheep Fire is about 7,500 acres with 20 percent containment, Forest Service says
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About 4,000 people in San Bernardino County forced from their homes
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Despite more cooperative weather, people not let back into homes yet
Back fires have been set to protect homes at the eastern edge of @placeholder, authorities said.