Between roughly 80,000 and 12,000 years ago, a massive glacier covered much of what is now Canada and the United States. An expanse of land then connecting Alaska and Siberia was eventually covered by water as the great icecap melted, and Bering Strait grew to separate North America from the Asian continent.
The first to cross this land bridge were ancestors of the Paleo-Indian peoples -- big-game hunters following their prey. It is thought that upon their arrival to the North American continent, these hunters continued through a corridor of land that had been left exposed between two sections of the icecap. When exactly -- between 20,000 and 12,000 years ago -- this migration occurred is much debated among specialists.
While the land-bridge theory is almost universally accepted, some believe that the first travellers to North America may have come by water. There is presently no solid evidence to support this.
First Nations and Inuit
Most of what we know about the first inhabitants of North America, the ancestors of today's First Nations and Inuit, is due to the work of archaeologists. These specialists have generally divided the past into two periods: the historic period, for which we have written accounts; and the prehistoric period, prior to the existence of written records. Archaeological work on the prehistoric period -- studying stone tools, bone chips, and faunal and other remains -- is invaluable because few other types of information are available.
Certain key discoveries have contributed to our knowledge of these people. In 1927 a fluted point was uncovered near the town of Folsom, New Mexico, that dated back to about 8,500 B.C. Similar artifacts from the same time period have since been discovered in Canada. In 1975 a discovery was made at the Bluefish Caves in the mountains of the northern Yukon Territory. These three small caves contained the bones of ancient animals, many of which showed signs that they had been butchered. As well, archaeologists found stone tools that could only have been made by humans. One tool, a burin or stone chisel, is the oldest evidence of human occupation in Canada. Using a technique known as radiocarbon dating, scientists were able to conclude that the caves were used intermittently by hunting parties between 25,000 and 12,000 years ago.
Over the millennia these ancient peoples dispersed throughout North America and developed subsistence strategies particular to their environments. For example, ancestors of today's Inuit learned how to cope with their harsh environment by using the northern resources to their advantage and developing unique tools. Those migrating to the coastal and prairie regions of the country did the same, adapting to their surroundings through ingenuity and invention.
By the time of first contact with the Europeans, there were millions of inhabitants already dispersed all over "Canada," who spoke many different languages. Although seemingly primitive to the European sensibilities of the time, these nations had highly developed ideas on governance, industry, religion, medicine, and society. European exploration of Canada would have been much more difficult had explorers not been able to rely on the Native peoples, with their intimate knowledge of the landscape.