By most estimates it was a bloodbath.
Our story begins 9,000 or 10,000 years ago about 20 miles west of Idaho Falls. A group of native people lined up barriers to funnel bison into the sharp drop off of a collapsed lava tube cave. Then they chased the bison into the trap. About 60 hapless creatures stampeded into the hole and were speared and butchered.
Fast forward several thousand years to 1965. A group of amateur archaeologists called the Upper Snake River Prehistoric Society became interested in three lava tube caves about 20 miles west of Idaho Falls.
One in particular, Owl Cave on land owned by Leonard Wasden, showed promise. With the help of professional archaeologist B. Robert Butler of the Idaho State College Museum in Pocatello, they began excavations. Excavations continued into the 1970s with other teams from Idaho State University and the Upper Snake River Prehistoric Society.
What the diggers found was incredible. Besides prehistoric bison remains, researchers found bones of mammoths, camel, dire wolf and lion, all with the presence of human tools and even pottery. Evidence suggests that mammoths may have been around longer on this side of the Rocky Mountains than on the east side.