Mason County Washington (Historic Districts) has 4 places on the National Register of Historic Places including 3 places of Statewide significance. Significant places include Cushman No. 1 Hydroelectric Power Plant, Cushman No. 2 Hydroelectric Power Plant and Schafer State Park.
Some of the country's most noteable architects helped create the Mason County places including Clarence Clyde "Doc" Palmer, Tacoma Light Dept., Tacoma City Light, Bonnel,J.E. and & Sons. Prominent architectural styles found in Mason Country are Classical Revival and Other.