A ceremony marking the new status will be held during the 16th annual Tofino Shorebird Festival (May 3-5).
The network, comprising more than 80 sites from Alaska to Tierra del Fuego at the southern tip of South America, is dedicated to conserving shorebird species and their habitats across the Americas.
Local aboriginal and landowner groups supported the Tofino designation, says Bird Studies Canada, a national conservation group that worked on the project.
The site on the west coast of Vancouver Island has been renamed the Tofino Wah-nah-jus Hilth-hoo-is Mudflats, recognizing the involvement of First Nations. Wah-nah-jus and Hilth-hoo-is are two nearby mountain peaks.
Flocks of sandpipers, plovers, whimbrels and other shorebirds pass through the Tofino area each spring, from late April through May.
The shorebird reserve designation covers 5,533 hectares and applies to Arakun Flats, Ducking Flats, Doug Bank's Flats, Maltby Slough, South Bay and Grice Bay, as well as the popular Chesterman Beach and Long Beach.
Festival events will include a kayaking tour through the Grice Bay mudflats to shorebird habitats accessible only by water.