Update, 5:25 p.m.:
Forward spread has been stopped, Cal Fire says. Teams will likely be on scene for at least two hours.
Update, 5:11 p.m.:
Cal Fire says the 4-acre fire has a moderate rate of spread, but air tankers and engines are making progress on the blaze.
Cal Fire is responding to a vegetation fire near River Road and Santa Margarita Truck Trail in Santa Margarita.
The fire is about 4 acres, according to a tweet by Cal Fire at 4:15 p.m.