According to the Ventura County Fire Department, the so-called Elizabeth fire was moving at a "moderate" pace as firefighters from multiple agencies responded on the ground and in the air.
The fire is now 20 percent contained.
Officials say two firefighters were transported to a local hospital for "general illness/exhaustion." No structures were threatened.
At least one air tanker was seen dropping crimson-colored Phos-Check on the rolling hills at the scene as firefighters worked to get an upper hand on the flames.
The cause of the blaze is unknown.