Mitlenatch Island is located approximately 30 kilometres (19 mi) northeast of Courtenay, British Columbia in the Strait of Georgia.

In 1959, the Province of British Columbia purchased Mitlenatch Island from a local family, and in 1961 it was designated as a Provincial Nature Park.

[citation needed] Mitlenatch Island Nature Provincial Park is home to the largest seabird colony in the Strait of Georgia.

Glaucous-winged gulls, pelagic cormorants, pigeon guillemots, rhinoceros auklets and black oystercatchers also return to Mitlenatch each spring to breed.

[citation needed] These snakes are frequently encountered along trails and in beach and tide pool areas, where they feed on small fish such as sculpins and blennies.