A 68-year-old man from Colorado Springs died Thursday morning on the Crested Butte side of West Maroon Pass, according to authorities.

The man and his son had taken a shuttle to the trailhead outside of Crested Butte and were hiking the popular route to Aspen.

“They were almost at the summit, roughly at 12,000 feet, when the gentleman (collapsed),” said Marjorie Trautman, public information officer for the Mount Crested Butte Police Department. It is believed he died almost immediately, she said.

The son, in his 30s, started heading back to the trailhead for assistance. A trail runner came across the body and later made contact with the son. They made arrangements for the trail runner to head to the settlement of Crystal where there is access to a radio for emergency responders. The son returned to his dad.

Carbondale Fire Department was informed of the death. The information was passed on to the Pitkin County Sheriff’s Office, then it was determined the death occurred in Gunnison County. Mount Crested Butte Police Department contracts to handle incidents for that neck of the woods, so it coordinated a recovery by Crested Butte Search and Rescue.

The name of the deceased and the cause of death weren’t immediately available.