NORRIDGEWOCK — A man riding a motorcycle was severely injured around 1 p.m. when he slid into an 18-wheeler.

The crash closed the route between Norridgewock and Skowhegan for at least two hours.

The tractor-trailer, driven by Maurice Ramsdell, 50, of Dexter, was heading toward Norridgewock and attempted to make a left-hand turn, Somerset County Sheriff’s Deputy David Cole said at the scene.

The motorcycle tried to pass the truck on the left and collided with the portion below the driver’s side door. The driver was not wearing a helmet.

Police did not release the name of the motorcycle driver as his family had not yet been notified. He was taken by ambulance to Redington-Fairview General Hospital in Skowhegan.

There, a LifeFlight helicopter took him to another hospital. Police did not know which hospital.