Home Postcodes by state SA 5139 Postcode 5139 5139 is the postcode for Forest Range, SA. Localities with postcode 5139Forest RangeSA Postcode 5139 State or territory South Australia (SA) Localities 1 Council area Adelaide Hills Council area based on Australian Bureau of Statistics data (ASGS Edition 3), CC BY 4.0. Postcode 5138 · Postcode 5140