Sonora Island is located off the mid-east coast of Vancouver Island. Fierce tidal channels surround the island, which was considered, until the 1870s,
Valdes Island, along with Quadra and Maurelle islands—these three islands did not receive their individual names until 1903.1
The 174 square km Sonora Island was named after the Sonora, an 11 m Spanish vessel that sailed west coast waters in the 1770s.2
1. Andrew Scott, The Encyclopedia of Raincoast Place Names (Madeira Park, BC: Harbour Publishing, 2009), 556.