The fire, initially reported at 5 acres, was reported in the 1100 block of Thompson Lane at 3:23 p.m., spokesman Dave Welch said.
The blaze spread to 20 acres and was bumping up against residences, Welch said.
As of 4:45 p.m. he said no buildings had been damaged, however residents on Thompson Lane, Skillman Lane and Magnolia Avenue were notified about the blaze and told to shelter in place.
He said an official evacuation order was not called.
