Belfair, Washington and Theler Wetlands. Belfair is an unincorporated community in Mason County, Washington, United States. Located at the head of the Hood Canal, a branch of Puget Sound, it serves as the commercial center of North Mason. The Theler Center, at the southern end of Belfair, hosts a community hall, exhibit center, four separate walking trails meandering through 135 acres of tidal wetlands, offering boardwalks and well-groomed paths with scenic views of Hood Canal, Union River, and a tidal estuary. Birders flock to the area to view kingfishers, heron, bald eagles and other birds. The wetlands and surrounding lowland forest are also home to fox, deer, and other creatures.