Cal Fire was fighting a vegetation fire southwest of Tracy in San Joaquin County on Wednesday afternoon.
The blaze, which started shortly before 3:30 p.m., burned near Interstate 580 and Corral Hollow Road at the edge of the Carnegie State Vehicular Recreational Area, according to spokeswoman Pam Temmermand of the Cal Fire Santa Clara unit.
As of 4:30 p.m., the fire burned between 80 and 100 acres and was 30 percent contained, Temmermand said. It was no longer a threat to any structures and no injuries had been reported.
In an update at 6:57 p.m., Cal Fire said the fire increased to 500 acres but reduced the acreage to 283 in another update at 7:36, citing “better mapping,” and said containment was at 50 percent.
Cal Fire and the Alameda County Fire Department responded to the blaze. Firefighters will monitor the fire lines throughout the night and Thursday, Cal Fire said.