Prehistoric human bones found in cave.

Researches announced this month that they have identified a partial skeleton found in a Colorado mountain cave as that of a 35- to 40-year-old man who died about 8,000 years ago.

Radiocarbon dating of the human remains indicates that they are among the oldest ever found n North America. The frozen man recently found in the Austrian Alps met his demise about 5,300 years ago (SN: 4/18/92, p.253). The new discovery also provides the earliest North American evidence of high-altitude human activity: The bones lay in a cave more than 10.000 feet above sea level.

"It was thought until recently that people from that time period [around 8,000 years ago] were only passing through this region by way of the mountain passes," says Patty Jo Watson of Washington University in St. Louis, lead archaeologist on the 19-member team that studied the ancient remains. "But this new evidence suggests that this man spent quite a bit of time in the area and clearly knew his way around."

The remains, discovered in 1988, include the skull cap, several arm and leg bones, a few ribs and vertebrae, pelvic fragments, four fingers bones, and 11 teeth.

This skeletal array was strewn about 1,000 feet from the cave's small entrance, located at the end of a narrow, winding passageway that requires considerable skill to negotiate. Smudge marks on the cave walls and charcoal fragments on the clay floor suggest that the man entered the earthen chamber with a torch, Watson maintains.

Her team found no ritual objects or other signs of burial in the cave. The cause of the man's death remains unclear, she adds.

Preliminary DNA analysis of a small bone sample shows a genetic arrangement characteristic of some Native American groups now living in regions south of Canada, Watson notes.