PARK CITY — Police are investigating the death of 78-year-old man who detectives say crashed on his mountain bike.

About 4 p.m. Friday, several people on mountain bikes came across a Park City man who crashed on the Nowhere Elks Mountain Bike Trail. Summit County Sheriff’s Lt. Andrew Wright said the crash happened at the base of a hill.

No one witnessed the accident, but investigators believe the man hit a large rock on the trail and was thrown from his mountain bike, Wright said. The man’s front tire was “significantly bent” and the man was found several yards away from his bike.

An autopsy will determine whether the man was killed in the crash or if there were any other contributing factors. The man’s name was not immediately released pending notification of family members.