Photo: Andrew Goff.

The driver, a 63-year-old man, and the passenger, a 63-year-old woman, are both from Orangevale, Calif.

From the California Highway Patrol:

On June 11, 2016 at approximately 1634 hours, a 2016 Special Construction motorcycle with two riders was traveling southbound on US 101, north of Richardson’s Grove. For reasons still under investigation, the motorcycle left the roadway and struck a dirt embankment. As a result of the collision, both the driver and passenger were ejected from the motorcycle and sustained major injuries. Due to his extensive injuries the driver was air lifted from the scene to Mercy Medical Center in Redding, CA. The passenger was transported by ground ambulance to St. Joseph Hospital in Eureka, CA.

During this incident, US Highway 101 was closed to both northbound and southbound traffic for approximately one hour. All traffic was diverted through Lake Benbow Drive. The cause of this collision is still under investigation, however at this time drugs or alcohol do not appear to be a factor.

Agencies on scene we Cal-Fire, Humboldt County Sheriff Department, State Parks and the CHP. This collision remains under investigation by the California Highway Patrol.