The Paisley Caves or the Paisley Five Mile Point Caves complex is a system of eight caves in an arid, desolate region of south-central Oregon, United States north of the present-day city of Paisley, Oregon. The caves are located in the Summer Lake basin at elevation and face west, carved into a ridge of Miocene and Pliocene era basalts mixed with soft volcanic tuffs and breccias by Pleistocene-era waves from Summer Lake. One of the caves may contain archaeological evidence of the oldest definitively-dated human presence in North America. The site was first studied by Luther Cressman in the 1930s.
Scientific excavations and analysis in the Paisley Caves since 2002 have uncovered substantial new discoveries, including subfossil human coprolites with the oldest DNA evidence of human habitation in North America, various artifacts, and animal remains. The DNA was radiocarbon dated to 14,300 BP or roughly 12,000 BC. The caves were added to the National Register of Historic Places in 2014.
In the summer of 2007, a field school from the University of Oregon identified the oldest human DNA yet discovered in the Americas. This assertion is based on analysis of several coprolite samples found in the Paisley Caves complex. In total, workers have obtained over 280 radiocarbon dates and DNA analysis from more than 60 coprolites from the Paisley Caves. Coprolite analysis at varying ages revealed that these occupants were omnivorous, eating a combination of foraged plants, seeds, small mammals such as rodents, fish, and insects like beetles. Knowledge of this omnivorous mode of sustenance supports the notion that the coprolites are human in origin. Other authors have questioned the authenticity and relevance of the evidence gathered from ancient DNA and stratigraphy and challenge the morphological assignment of the coprolites to humans.
The coprolites were found in the same level as a small rock-lined hearth some below the modern surface. Also discovered at that level was a large number of bones from waterfowl, fish, and large mammals, including extinct camels, horses, and bison.