Wilson Butte Cave, on southern Idaho’s Snake River Plain, is an archaeological site formed within a volcanic pressure ridge of ancient basalt from nearby Wilson’s Butte. Its importance rests on a remarkably deep human record: archaeologists are certain people lived there at least 10,000 years ago, and excavator Ruth Gruhn argued for occupation as early as 14,000 to 15,000 years ago, making it among the oldest evidence in North America. The cave was likely used early as a bison hunting base. Finds from the site also helped trace cultural links between the Fremont and later Shoshone peoples.