On Sunday, June 11, 2023, at approximately 2:41 P.M., the Oregon State Police responded to a multi-vehicle crash on Hwy 18, near milepost 14, in Tillamook County. The preliminary investigation indicated a white Ford Transit van, operated by William Nicolas Calderon (20) of Lincoln City, was traveling westbound on highway 18 when the vehicle left its lane of travel, and side swiped a Gray Honda Pilot, operated by Joseph Daniel Davis (59) of Dallas. The Ford Transit then side swiped a Gray Ford Ranger, operated by Kory Lee Thomas (51) of Salem. The Ford Transit then collided head on with a gray Subaru Crosstrek, operated by Jennifer Marie Ahlstrom (48) of Portland. The operator of the Ford Transit (Calderon) was transported to a local hospital for treatment. The operators of the Honda Pilot (Davis) and Ford Ranger (Thomas) were not injured. The operator of the Subaru Crosstrek (Ahlstrom) was seriously injured and transported by air to a local hospital. Two juvenile passengers were transported by ground ambulance for treatment. The roadway was impacted for approximately 5 hours during the on-scene investigation. The cause of the crash is being investigated. At this time, OSP is unable to release further information due to the continuing investigation. OSP was assisted by the Polk County Sheriff’s Office, Grand Rhonde Fire, North Lincoln Fire, Pac West Ambulance, and ODOT.