The crash was reported at around 7:54 p.m. in the southbound lanes of the interstate near Exit 105, according to Trooper Guy Gill.
The rider was injured and taken by ambulance to Providence St. Peter Hospital in Olympia. The motorcyclist was the only one involved in the crash.
"Our investigation revealed that the rider is drug impaired," Gill said. "A blood draw was conducted and the results are pending."
The State Patrol is still investigating.
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