It is located between Mathieson Channel and Lady Trutch Passage, and is flanked by Dowager Island (to the northwest), Lady Douglas Island (to the west), and a long finger shaped peninsula of the Canadian mainland to the east.

[1] Lake Island is not a lake island, as it is in an inlet of the Pacific Ocean, and lies only some 6 kilometres from the open sea.

Lake Island is part of a volcanic area called the Milbanke Sound Group and includes monogenetic cinder cones.

Basaltic tuff breccias on Lake Island originated from Helmet Peak.

This article about a location on the Central Coast of British Columbia, Canada is a stub.