The Tofino mudflats are located on both sides of the Browning Passage near the town of Tofino, British Columbia. There are six mudflats in total with these being known locally as Arakan Flats, Ducking Flats, Doug Bank's Flats, Maltly Slough, South Bay, and Grice Bay. About half of the 32 km2 area is mudflats that are left exposed during low tides. These mudflats are partially covered by dense growths of eelgrass and algae. The upper tide limit is lined with salt marshes and forests. Chesterman Beach, which is located on the seaward side of the Esovista Peninsula, is a clean sand beach with driftwood tangles along the upper tide line. This beach is an important roosting area for Western Sandpipers.

The Tofino mudflats are a critical stopover site for migrating Western Sandpipers. In southern British Columbia the site is second only to the Fraser River Delta in terms of usage by this species. The peak counts of 16,000 Western Sandpipers in May 1988, 23,000 in August 1989, and an average autumn peak of 35,000 at Chesterman Beach are reported to be amongst the highest recorded on the west coast of Canada for this species.

Elsewhere in British Columbia, studies on Western Sandpipers fitted with miniature radio transmitters in spring indicated an average stopover period of about three days. Assuming that this three-day stopover period also applies to Tofino, the population using this area in the spring may be as high as 45,000, and as high as 164,000 in the fall. These numbers represent at least 2.25% of the global population during spring and possibly as much as 8.2% of the global population during fall. In addition to Western Sandpipers, the Tofino Mudflats also provide habitat for a variety of other shorebird species including dowitchers, Dunlin, Least Sandpipers, Black-bellied Plovers, Greater Yellowlegs, Sanderling, Whimbrel and American Black Oystercatchers. The adjacent areas are also important as a wintering area for variety of waterfowl. Some of the more abundant species include Trumpeter Swan, Mallard, Northern Pintail, American Wigeon, Surf Scoter, Bufflehead and various species of loons and grebes.

The site is also important as a late summer feeding area for the northwestern population of the Great Blue Heron (ssp. fannini). Up to 100 individuals occur on the mudflats each August. This represents approximately 1.1% of the global population of this subspecies. The fannini ssp. of the Great Blue Heron has been identified as nationally vulnerable.

The Tofino mudflats are the only area on the west coast of Vancouver Island known to support large numbers of shorebirds. They have been identified by CWS as a potential WHSRN site. Some have noted that the Tofino Mudflats are second only to the Fraser River Delta in importance as a feeding and resting site for Western Sandpipers in British Columbia. Currently only a small portion of the site (3,067 ha) is protected as a Wildlife Management Area.