Motorcyclist dead after collision with tandem bicycle in canyon

A significant stretch of Lefthand Canyon was closed Saturday afternoon following a fatal collision involving a motorcyclist and two people on a tandem bicycle. 

A 58-year-old man aboard the motorcycle was pronounced deceased at the scene.

Two adults, a 64-year-old man and a 45-year-old woman, both from Longmont, were on a Co-Motion Erimera tandem bicycle. Both were taken to area hospitals - the man flown by medical helicopter and the woman transported by ground ambulance. The man suffered serious injuries and the woman, the passenger, suffered moderate injuries.

The crash was called in shortly after noon, according to Trooper Gabriel Moltrer of the Colorado State Patrol. 

CSP investigators believe the motorcyclist's KTM Adventure R-1190 crossed the center line while travelling westbound at mile marker 12 of Lefthand Canyon Drive. The motorcycle struck the front tire of the eastbound tandem bike, causing both to crash. The motorcycle and its rider continued off the left side of the road, struck a tree branch and went down an embankment. Both the motorcycle and its rider landed in Lefthand Creek.

One of the bicyclists landed in one lane of traffic. The other was found on the road's shoulder. 

Moltrer said excessive speed is a suspected factor in the accident. Alcohol and/or drug impairment is not. 

All involved were wearing helmets.  

Initial calls to 9-1-1 reported the motorcyclist had tried to drive away from the initial contact with the bicycle. But Moltrer said CSP investigators found no evidence this was a hit-and-run.

Traffic in the canyon was re-opened just before 6 p.m.