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.