The station broadcasts to the Limestone Coast region including the towns of Naracoorte, Millicent, Robe, Kingston, Bordertown and Keith.
The station began broadcasting as 5MG in 1955, with a single transmitter which could only serve listeners in the Mount Gambier region.
The transmitter in the years to come was modified and relocated to the town of Nararcoote, which resulted in Mid and Upper South East residents being able to listen to 5MG.
The station's studios on 31 Penola Road were opened in the late 1950s, and were upgraded in 2006 to digital equipment, just a few years behind ABC Riverland.
As of 2021, there are a total of ten full-time staff and several casuals at ABC South East SA.