The Bluefish caves are an archaeological site located in the northern Yukon, 50 kilometers southwest of Old Crow. The 3 caves, actually limestone shelters, occur at the base of a limestone bedrock ridge, along the mid-course of the Bluefish River, about 200m above the valley floor. The caves reveal the oldest evidence of human occupation in North America. Preserved within the sediments are the artifacts that have provided information which has allowed scientists to reconstruct the history of the caves in surprising detail. Research being done at the Bluefish Caves, is led by archaeologist Jacques Cinq-Mars of the Archaeological Survey of Canada, Canadian Museum of Civilization. Initial research was carried on in the 1970’s and 1980’s.
Although the soil layers at Bluefish Caves are little more than a metre thick, they preserve a record of events and past environments, spanning approximately 24,000 years. The soil layers or stratigraphy exposed in the excavations have remains of past vegetation and the bones of the Ice Age mammals that once roamed in the area. Pollen and plant remains of the loess (wind-blown silt) layers in the caves reflect a vegetative cover dominated by grasses and herbs, the typical vegetation of the glacial maximum. The organic rubble layers above preserve a sequence marked first by a rise in shrub birch, followed by spruce, as forests once again moved into the northern Yukon as temperatures and rainfall increased at the end of the Ice Age.
The bones of animals in the loess layer are principally those of Ice Age species: horse, bison, mammoth, wapiti, saiga antelope and caribou. Dates on a horse femur, a mammoth scapula and a mammoth limb bone provided dates of 13,000, 15,500 and 24,000 years before present, indicating use of the cave by both animals and people in the last millennia of the glacier period. Meticulous microscopic examination of the bones from the Bluefish Caves has revealed butchering and cut marks on bone, including the bone of mammoth, caribou and horse. There is no sign of human use of the cave after the end of glaciation. In addition to larger Ice Age mammals, remains of smaller carnivores, rodents, birds and fish were also found in the Caves.