The northern part includes the village of Pointe au Baril on the mainland and most of the geographic townships of Shawanaga and Harrison.

This covers the islands and shoreline of Georgian Bay from the Twin Sisters (at the northern boundary of Carling Township) north to Charles Inlet and the Naiscoot River, a few miles south of Britt.

The southern part consists of the geographic townships of Cowper and Conger that includes the islands and shoreline of Georgian Bay southwest of Parry Sound, from Twelve Mile Bay (at the District of Muskoka boundary) to Wasauksing First Nation and up the South Channel almost to the town of Parry Sound.

[3] The township is characterized by numerous islands (hence its name) and bays that attract large numbers of vacationers and boaters in the summer.

[3] On January 1, 1980, the townships of Georgian Bay South Archipelago and Georgian Bay North Archipelago were formed out of unincorporated geographic townships from the Parry Sound District, primarily in order to provide proper planning in the islands and waterways of the area.