 Archaeological evidence of pre-Clovis people points to the South Carolina Topper Site being 16,000 years old, at a time when the glacial maximum would have theoretically allowed for lower coastlines.It has often been suggested that an ice-free corridor, in what is now Western Canada, would have allowed migration before the beginning of the Holocene, but a 2016 study has argued against this, suggesting that the peopling of North America via such a corridor is unlikely to significantly pre-date the earliest Clovis sites.The study concludes that the ice-free corridor in what is now Alberta and British Columbia "was gradually taken over by a boreal forest dominated by spruce and pine trees" and that the "Clovis people likely came from the south, not the north, perhaps following wild animals such as bison".