Entry from June 19, 2012
White Fort State (Oregon nickname)
Oregon was called the White Fort State, Hard Case State, Beaver State and Pacific State in The Teachers World (September 1893). The “White Fort State” nickname appears nowhere else in print, but the nickname indicates that Oregon was once known for its white forts.
Google Books
September 1893, The Teachers World, “For Interesting the Geography Class” by Gertrude E. Thompson, W. Medford, Mass., pg. 17, col. 2:
Oregon— White Fort State; “Hard Case State”; Beaver State; Pacific State.