The longtime mystery of a missing hiker at Rocky Mountain National Park appears to have been solved.

Skeletal remains found in Rocky Mountain National Park in August 2020 are thought to belong to Rudi Moder, a man from West Germany who disappeared in the park more than 38 years ago, a news release from the park said Thursday.

Moder, a 27-year-old man living in Fort Collins in 1983, was an “experienced mountaineer” headed to Cameron Pass on Feb. 13 of that year for a two- or three-night ski and mountaineering trip over Thunder Pass in Rocky Mountain National Park, the release said.

Moder’s roommate reported him missing Feb. 19 after he was overdue to return, officials said.

Search teams scoured the area, but a foot of snow that fell in the Never Summer Mountains impeded the mission, the release said. Rescuers searched on skis, snowshoes, by air and with avalanche dogs for four days. They found a snow cave with Moder’s sleeping bag, gear and food stockpile.

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Numerous searches conducted through spring and summer of 1983 and periodically in following years did not recover Moder’s remains, the release said.

Then, in August of 2020, a hiker found skeletal remains in Skeleton Gulch near avalanche debris in the same area as the initial search, officials said. Rangers started an investigation, but the Cameron Peak fire, followed by early snowfall, stifled its progress.

During the summer of 2021, rangers continued to search the area and found skis, poles boots and a bag all believed to belong to Moder.

The Grand County Coroner’s Office tried to identify the remains using dental records, but the results were inconclusive, according to the release.

Officials worked with the German government for repatriation, family notification and dental record analysis, the release noted.

The recovery of the remains ends a four-decade-long cold case.