The Denver-bound lanes of U.S. 36 remain closed between Church Ranch and Sheridan boulevards while Westminster police investigate a fatal motorcycle accident.

The accident took place just west of the Sheridan Boulevard onramp onto U.S. 36 at about 8:25 p.m., according to investigator Cheri Spottke of Westminster police. It is believed the motorcyclist crashed first and a larger accident resulted, Spottke said. The motorcyclist was declared dead at the scene. Alcohol is suspected to have played a role in the accident.

"We know a single motorcycle hit the median and went down," Spottke said. "And at least one, and possibly three, cars hit the cyclist."

Denver-bound traffic on U.S. 36 is being diverted onto Church Ranch Boulevard or 104th Avenue, Spottke said. She expects the Denver-bound lanes of the highway to remain closed between Church Ranch and Sheridan for at least the next two hours while police investigate the accident.