The closest rifle range, that I know of, is in Duarte.
San Gabriel Valley Gun Club, 4001 Fish Canyon Road, Duarte, CA 91010.
Facilities include: Outdoor Pistol (15, 25, 50 yds), Outdoor Rifle (50, 100, 200 yds), Muzzleloading, Trap, Skeet
Hours of Operation: Tu - Su 8am-4:45pm
Range Access: Public
Web Site: www.sangabrielvalleygunclub.com
try this site
Has listings for ranges in the state