Jorge Hernandez-Oropeza is accused of molesting the girl numerous times while she was being babysat by his mother in 2010 and 2011.
Deputies say they've identified two additional victims and are calling on any other victims to come forward.
Hernandez was booked at the Big Bear Jail and was being held on $250,000 bail. Authorities also say he is an illegal immigrant and is being held on a no-bail immigration hold.
Anyone with information on this case should call the San Bernardino County Sheriff's Department at (909) 387-3615.