Union is a small census-designated place in Mason County, Washington, United States. The community lies along the southern shore of Hood Canal, at an area known as "the Great Bend". The U.S. Census reported a population of 631 inhabitants in the 2010 census. The ZIP Code for Union is 98592.State Highway 106 is the main route through Union, leading to Belfair farther north, and Potlatch and US Highway 101 to the south.Local attractions include a working farm and roadside market, a golf course, marinas and public boat launch sites, and the deep saltwater fjord of Hood Canal. Visitors come to the area for activities including boating, fishing, hunting, shellfishing, sea kayaking and birding. Union was named one of America's twenty prettiest towns by Forbes Traveler.Union was founded and named in 1858 by merchants Willson and Anderson.