CENTER TWP — A motorcyclist remains in critical condition at a Pittsburgh hospital following a weekend crash.

Ronald Litzinger, 36, of Butler suffered “life-threatening” injuries Saturday evening when he crashed into several trees along Route 308 near Holyoke Road, authorities said.

State police said Litzinger was northbound on a Harley-Davidson about 6:30 p.m. when he approached another vehicle from behind on Route 308. The other vehicle was stopped or had slowed to make a left turn onto Belleshire Drive.

He apparently was unable to stop in time and veered to the left of the vehicle. His motorcycle went off the west side of the road and traveled into a yard, hitting several trees.

He was unresponsive when Unionville volunteer firefighters and a Butler Ambulance Service crew got there. Police said he was not wearing a helmet.

Litzinger had not regained consciousness by the time a medical helicopter later landed in a field next to the road and flew him to AGH.

A hospital spokeswoman said he is listed in critical condition.