List of Washington state symbols
While some of the symbols are unique to Washington, others are used by multiple states. For example, the willow goldfinch (also known as the American goldfinch), Washington's state bird, is also an official symbol for Iowa and New Jersey. Washington's state grass, bluebunch wheatgrass, is also a symbol for the state of Montana. The square dance and apple are commonly used state dances and state foods, respectively. While most states have an official motto and nickname, Washington's motto ("Al-ki", meaning "by and by" in Chinook Jargon) and nickname ("The Evergreen State") have never been officially adopted by the Legislature.
Washington state tartan
Consisting of a green background with stripes of blue, white, yellow, red, and black, the state tartan of Washington was designed by Margaret McLeod van Nus and Frank Cannonito in 1988 to commemorate the Washington centennial celebration. It was registered with the Scottish Tartans Society after its adoption by the state legislature in 1991. The colors represent various aspects of nature: green symbolizes rich forests of the state; blue the lakes, rivers and ocean; white the snow-capped mountains; red the apple and cherry crops; yellow the wheat and grain crops; and black the eruption of Mount St. Helens.SB 5047 - WA State Legislature