The U.S. Mint's bicentennial commemorative quarter for Washington state features a leaping salmon, Mount Rainier, western hemlocks (the state tree), Washington's nickname; "The Evergreen State," and the date Washington became the 42nd state: 1889. Public domain image on Wikipedia.
Unofficial Nickname for the State of Washington
Washington was nicknamed "The Evergreen State" by pioneer C.T. Conover (a Seattle realtor and historian) for its abundant evergreen forests. All State Nicknames
Although "The Evergreen State" nickname is very well-known and widely used, it has not been officially adopted by Washington's state legislature.
In 2023 the state senate proposed bill SB 5595 to make the nickname official. In February the senate voted 49-0 to approve. It still needs to be approved by the house and then signed by the governor to become official.