SAN JOAQUIN COUNTY (CBS SF) — A large vegetation fire near the Carnegie State Vehicular Recreational Area in San Joaquin County has burned hundreds of acres, Cal Fire said on Wednesday.

Dubbed the Hollow Fire, the blaze was first reported around 3 p.m. off West Corral Hollow Road, southwest of Tracy.

The fire was initially under 100 acres and 30 percent contained around 4 p.m., but Cal Fire said it ballooned–by 6:30 p.m., the fire had burned over 500 acres and was still 30 percent contained. Officials said the wind and terrain were causing firefighters difficulties.

At 7:38 p.m., Cal Fire said the fire was 50 percent contained and had been reduced to 283 acres due to better mapping.

Cal Fire and the Alameda County Fire Department are working throughout the night and into tomorrow to contain the fire

No structures are threatened and no evacuations have been ordered, Cal Fire said.

This is a developing story. Stay with CBS SF for the latest updates.