TULSA COUNTY, Oklahoma - The Oklahoma Highway Patrol says a 29-year-old Oologah man was critically injured when his motorcycle struck a pickup on Highway 169 south of Owasso Wednesday morning.

Troopers said southbound traffic had slowed just before 7:30 a.m. when Robert McAfee's 2014 Harley Davidson went off the highway to the left and struck the rear of a disabled 2003 Dodge pickup parked on the inside shoulder.  

The OHP report states McAfee, who was not wearing a helmet, was thrown from the bike and landed on the highway.  

The truck's driver, 53-year-old Nora Adams of Claremore, was treated and released from a Tulsa hospital.

The OHP says the crash backed up southbound traffic on 169 just north of 56th Street North for several miles until the wreckage was removed about an hour later.

The cause of the collision remains under investigation by the OHP.