RIVERSIDE (CBS) — A stubborn brush fire — at  2000 acres and counting — burned in Riverside County Saturday.

Authorities say no structures are threatened.

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The fire is burning near Potrero Road and Wolfskill Extension Track Trail in the city of Beaumont.

No injuries have been reported.

The cause of the fire is under investigation.

The Highland fire is being fueled by 15-20 mph winds, according to officials.

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No evacuations are planned as of 11 p.m. Saturday. Felecia Hamad, a Beaumont resident says firefighters have told residents to be ready to leave at a moment’s notice. “They told me some of the documents we should have together just in case we had to go, where our pets would  go.”

Hamad  is concerned. “There’s so much brush, especially inside our property here, on the walking trail it’s just surrounded by the dry brush…and my  home is not far from that walking trail so, of course, it’s a concern to me.”

KCAL9 and CBS2 reporter Rachel Kim spoke to firefighters trying to get the upper hand on the blaze.

As night fell she said about 300 firefighters continued to battle the stubborn blaze.

Captain Rick Griggs of CAL Fire said, “It’s very steep and rocky terrain. It’s very difficult to access. It’s very remote and limited.”

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Still, he says firefighters are making progress. “Our air tankers and water drop helicopters are effective. They are the only thing actually reaching the fire  right now. We’ve got hand crews working their way to it, but we can’t just go up to the fire  where it’s actually burning. We got to work from where it started.”