MIDDLEBURG, Fla. -

A motorcyclist was airlifted to UF Health Jacksonville on Wednesday with life-threatening injuries after a single-vehicle crash on Dolphin Avenue North in Middleburg.

According to the Florida Highway Patrol, Douglas Sheppard 39, was traveling northbound on Dolphin Avenue, which is a two-lane road, and for unknown reasons crossed the oncoming traffic lane near John Cemetery Road, left the roadway on the left side of the road, went onto the shoulder and was thrown from the motorcycle.

The motorcyclist was not wearing a helmet.