Located on the corner of Rockford Drive and South Boulevard Del Perro, the Rockford Hills fire station is a large station with 3 bays. Unlike most stations, no fire truck is parked out front, yet the player may witness fire crew members standing outside the station. It could be that the apparatus is parked in one of the three un-openable garages. Because of it being larger than the other stations, it could very well be that this is the headquarters for the Los Santos Fire Department.
The De Santa residence is not very far from here.