The motorcyclist who suffered serious injuries in a collision with a car Saturday in Standish is in critical condition at a Portland hospital.

Ralph Belmont, 65, of Poland was taken by ambulance to Maine Medical Center after his 1976 BMW motorcycle collided with a car driven by Isabel Dawson, 19, of Portland around 4:37 p.m. A hospital spokesperson said Belmont was in critical condition Sunday evening.

Capt. Kerry Joyce of the Cumberland County Sheriff’s Office said in a news release that Belmont was traveling northbound behind Dawson’s 2014 Ford Focus when he attempted to pass her car on the left side. Dawson was making a left hand turn into a driveway at 1251 Pequawket Trail at the time. Belmont’s motorcycle struck the driver’s front side fender.

Witnesses told police that Belmont, who was wearing a helmet, was thrown from his bike. Belmont was unconscious when police arrived. Dawson suffered minor injuries. She was treated at the scene and released.

Alcohol is not suspected to have been a factor in the crash, according to Joyce. The cause of the crash remains under investigation. Both vehicles sustained extensive damage, police said.

The accident happened on Pequawket Trail – which is also Route 113 – between the Steep Falls section of Standish and East Baldwin.