A brush fire blackened about 50 acres in Irwindale Tuesday.
The fire broke out in the Santa Fe Dam Recreation Area and was burning in two acres of brush at about 5:25 p.m., according to the Los Angeles County Fire Department.
The fire grew to 20 acres, then to 50 acres by about 6:25 p.m.
No structures were immediately threatened, according to a fire department statement.
Fire crews and helicopters were still battling the blaze as of 6:30 p.m.