On the northern Oregon coast, adjacent to the town of Tillamook, Tillamook County. Tillamook Bay is a small, shallow estuary about 60 miles west of Portland on the Oregon Coast. It is approximately 6.2 miles long and 2.1 miles wide. The bay averages only 6.6 feet in depth over a total area of 13 square miles, or 8,400 acres. At low tide, about 50% of the estuary bottom is exposed as intertidal mud flats. The Bay receives fresh water input from five rivers and exchanges ocean water through a single channel in the northwest corner. The estuary provides habitat for numerous fish, shellfish, crabs, birds, seals, and sea grasses. The north end of Bayocean Spit hosts a population of State and Federally-listed (as threatened) Western Snowy Plover.
Tillamook Bay supports almost 25% of the northern- and central-coast wintering waterfowl population in Oregon (USFWS 1999). According to the 102nd Christmas Bird Count (12/15/01) there were approximately 7,500 waterfowl of 34 species in and around Tillamook Bay. American Wigeon numbers were approximately 4,000, Northern Pintail (200-600), Surf Scoters (200-500), Buffleheads (300-800) according to the Christmas Bird Counts of 2001, 2000 and 1999. Brown Pelicans use the Bay from May-December and peak in September with numbers in the low 100s (C. Roberts. Western Sandpiper numbers range 1,000-3,000 in September. Least Sanpiper numbers in the low 100s. Black-bellied Plovers, Semipalmated Plovers, Whimbrels, Sanderlings, Dunlins, and Short-billed Dowitchers are also seen (C.Roberts, CBC data). There are 2 rookeries around the Bay, which host Great Blue Herons numbering in the low 100s. One in Garibaldi which is quite large (up to 50 nests) and one near Kilchis Point in Bay City. The herons are year-round residents. (ODFW - Dave Nuzum). The Bay provides an important habitat for many birds migrating on the Pacific flyway. In addition, Bald Eagles and Brown Pelicans are both listed as threatened and both occur in and around the Bay.