The fire was reported around 3:15 p.m. Saturday near Tustin Ranch Road and Portola Parkway.
The flames came dangerously close to homes. Residents along Collar and Riehl avenues were evacuated from about a dozen homes, while some 75 firefighters and a water-dropping helicopter went to work.
A few hours later, firefighters had the blaze contained and residents were able to return to their homes.
No one has been arrested for starting the fire.