The wounded student, who was shot in the chest, was rushed to a hospital in stable condition with non-life-threatening injuries, according to Kittitas County Undersheriff Clay Myers.
Myers said it appears the shooting happened at about 10:30 a.m. in a residential neighborhood east of the school grounds. It was not clear exactly what prompted the shooting.
School staff immediately initiated lockdown procedures and called local law enforcement agencies, which responded and secured and searched both the Secondary School and the nearby Elementary School to verify that no further threats were present.
Roadblocks were set up and a perimeter was established around the residential development where the shooting is believed to have occurred and a search initiated for the shooter, but so far no suspect has been found and no description of the shooter has been released.
The school lockdown was later lifted, and normal after-school activities will resume this evening, said Principal Chris Brower. School will be on regular schedule on Friday.
The shooting is still under investigation, but there are no indications of any threats to the schools or any other students, Mysers said.