Collapsed lava tubes created the caves that make up the Croft Archaeological Preserve.
In 2013 the Conservancy purchased the Croft Archaeological Preserve. The caves 10,000 + year-old cave found here was a large game hunting and processinging location.
Located on the eastern portion of Idaho’s Snake River Plain, roughly 19 miles northwest of Idaho Falls, the preserve consists of three caves that were created by collapsed lava tubes. The most extensively studied of the three is Owl Cave, which was first recorded in the 1960s by Helen and Richard Gildersleeve of the Upper Snake River Prehistoric Society (USRPS).
Initial excavations in Owl Cave were under the direction of B. Robert Butler, of Idaho State University, from 1965 to 1971. The excavators, digging to a depth of six feet below the surface, uncovered numerous projectile points in conjunction with a layer of faunal remains that consisted of more than 70 bison. The evidence suggests that bison were driven, trapped, and then speared inside the cave. The large deposit of bison bones dates to roughly 8,000 years ago, and it rests on top of a layer of rock debris from ceiling or wall collapse.
Excavation in the caves at Croft Archaeological Preserve.
From 1974 to 1977, Susanne Miller, a doctoral student at Idaho State University, and the USRPS conducted excavations that dug beneath the collapsed rock debris, uncovering Folsom-style fluted points as well as mammoth, bison, pronghorn antelope, and camel remains. These deposit s date to over 10,600 years ago. The mammoth bones displayed signs of butchering and modification. This evidence shows that humans and mammoths co-existed, and that the mammoth was hunted as an economic resource. There is evidence of sophisticated processing technology of the mammoth bones, including percussion fracturing and marrow extraction.
For decades, the Croft family has owned and maintained one of Idaho’s most important archaeological sites. Their sincere interest in protecting the cultural resources on their property resulted in important research opportunities. The Crofts turned to the Conservancy for permanent protection of the site. The preserve consists of a 10-acre parcel containing the three caves. The Croft family will continue to play an active role in the management and stewardship of this place.
