Home Postcodes by state SA 5251 Postcode 5251 5251 is the postcode for 6 localities in SA: Bugle Ranges, Mount Barker, Mount Barker Junction, Mount Barker Springs, Mount Barker Summit and Wistow. Localities with postcode 5251Bugle RangesSAMount BarkerSAMount Barker JunctionSAMount Barker SpringsSAMount Barker SummitSAWistowSA Postcode 5251 State or territory South Australia (SA) Localities 6 Council area Mount Barker Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 5250 · Postcode 5252