UPDATE: Fire officials say the fire is expected to burn about 4,000 acres.
UPDATE (7:21 p.m.): The fire at Camp Roberts has grown to approximately 1000 acres -- and it is expected to top out at about 2000 acres, according to Camp Roberts officials.
Fire crews are expected to be there overnight, said a Camp Roberts information officer. And the fire is pretty well contained.
The fire began at about 3;15 p.m. and started at 100 acres before quickly jumping to 300 acres.
Camp Roberts was preparing for a controlled burn on June 3, so they and the land were fairly prepared for this, said a Camp Roberts information officer.
This is a developing story. Continue to check back for updates.
Fire crews are fighting a now 800 acre fire at Camp Roberts in San Luis Obispo County.
Four engine companies have responded: one from Camp Roberts Fire Department, two from Cal Fire and one from San Miguel Fire Department, according to Camp Roberts.
No structures are threatened at this time, and the cause of the blaze is still unknown.
The fire is expected to be contained within Camp Roberts' impact area and is unlikely to go outside of the camp, according to Camp Roberts officials.