Scientists return to Natural Trap Cave after 30-year absence

The entrance of Wyoming's Natural Trap Cave is just 15 feet long and 12 feet wide, big enough to let in sunlight and a few scientists. But as visitors quickly find out, that bit of sunlight illuminates an expansive cavern beneath -- 85 feet deep and 120 feet wide.
The smallish entrance is well hidden by the boulders and the sage and scrub brush that texture the foothills of the Big Horn Mountains. It can sneak up on visitors, and it's easy to see how a meandering creature might be grazing one minute and falling precipitously to its untimely death the next as the name of the cave suggests. But more than a name, at the bottom of the cave there's a pile of animal bones stacked 30 feet high -- stark evidence of the cavern's perils.
Scientists led a field trip of grad students to the cave once in the 1970s, but the Bureau of Land Management closed the cave shortly after. No one has entered in over 30 years. Now, BLM is letting scientists back in to rummage through the mound of ancient bones, some of them over 100,000 years old. Included in the pile are the fossils of lions, cheetahs, mammoths, bears and more.
The new expedition will be led by Des Moines University paleontologist Julie Meachen. Since scientists last entered, technology has obviously advanced quite a bit -- most importantly, the technology of DNA analysis.
The researchers hope analysis of any surviving DNA can help them learn more about the Pleistocene extinction, when quickly warming climate and the arrival of humans some 13,000 years before precipitated the extinction of dozens of species.
For the next two weeks, the scientists will descend and dig once a day -- setting up camp near the entrance and hauling box after box of bones to the surface.