It was one of at least five letters also sent to the governors of Idaho, Utah, Montana, and Nebraska. All appeared to come from a maximum security prison in Ely, Nevada.
Security officers in Montana opted to evacuate the second and third floors of the Capitol building. They treated the letter as a serious threat and thought there was a possibility there might be some explosives inside.
There weren't an evacuations in Olympia. State Patrol officers intercepted the letter to Gov. Locke in the mailroom around 10:30 a.m.
Washington State Patrol spokeswoman Nelsa Brodie said the envelope contained two matches and a piece of paper, arranged so the matches would strike and ignite the paper.
Security officers opened it in a way so the paper did not catch fire. The FBI is investigating.