Wilson Butte Cave



An Original Home on the Range -
Human Occupation of Wilson Butte Cave
Wilson Butte Cave provides some of the earliest evidence of human presence in Idaho and North America. The site is also important because it was occupied for such a long period of time. The cave was probably too damp and cold for human occupation until the Ice Age began to loosen its grip on southern Idaho, about 15,000 years ago. However, as the climate gradually warmed, the cave became a drier and more comfortable shelter.
When was it occupied?
The first unmistakable evidence of human occupation of Wilson Butte Cave dates from about 10,000 years ago. Ruth Gruhn, the archaeologist who excavated the cave, also uncovered cultural material that she believes shows that people used the cave as early as 15,000 years ago. Gruhn believes this conclusion is supported by the discoveries of human-modified bone fragments found in Layer E and artifacts and charcoal in Layer C. 
Other archaeologists, however, are less convinced that Wilson Butte Cave was occupied before 10,000 BP. They remain doubtful because only a few artifacts were found in association with the oldest time period, because the site was contaminated by modern human disturbance, and because they feel the artifacts may have eroded into layers where they didn’t originally occur. The excavation shows that Wilson Butte Cave was largely abandoned by 400 BP, after the bison largely disappeared from the area.

Why was it occupied?
Although the earliest dates of human occupation are debated, the reason for occupation of the cave is more certain. Artifacts from the cave tell us it was used primarily as a temporary shelter for bison hunters during the spring and summer. Bison were common on the Snake River Plain for thousands of years. They didn’t disappear completely from this area until the 19th Century. Bison populations appear to have decreased as the climate grew warmer and desert vegetation became more predominate, but hunting pressure by Native Americans also may have been a factor. 
Archaeologists have classified the cultural history of Wilson Butte Cave into five main time periods, which are called layers or strata. Visit the stratigraphy page for an explanation of the time periods and to see the interesting and wonderful artifacts discovered in each layer.

Next Page: Who Camped Here?

Remains of a bison-hide moccasin found in
Strata A at Wilson Butte Cave. Photo courtesy of The Idaho Museum of Natural History.

petrified bison skull courtesy the Sacajawea Center, Salmon
Petrified bison skull. Photo courtesy of The Sacajawea Center in Salmon, Idaho.  

Bison are still hunted today by tribal members. 

Occupation Period
Who Camped Here
What Was Found
Daily Life

Age Dating
Meet the Team


Out of the Ice Age
Idaho's Past Climate

The First People
A New Theory
Indian Tribes
Native Legends
Early Sites

and Gathering

Major Changes
Tools I
• Tools II
• Ice Caves
Gathering Plants
Food / Medicine


Teacher Pages

Resource Protection

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