His exact route remains unknown, but authorities believe he may have been trying to hike the Glacier Gorge Traverse on Aug. 29. The route is considered “difficult” terrain, and includes 11 peak summits over approximately 19 miles.

Grunwald’s vehicle was found parked at the Glacier Gorge Trailhead on Sept. 10, and search efforts began the next day, the release said.

Recovery operations — which included a helicopter and a team of rescue dogs — were made difficult by poor conditions, including snow, strong winds and windchills of 11 degrees on Saturday, according to the park.

Larimer County Coroner, James Wilkerson, performed the autopsy on Grunwald's remains, and determined the cause of death to be from multiple blunt force trauma injuries. Grunwald's death was deemed to be accidental, and he mostly died on August 29, 2020 from a fall.

Grunwald gave a Tedx Talk at Syracuse University in 2019, and spoke of being an environmental biologist and exploring ancient organisms in relation to humanity.