The First Americans, Part 3
But thewestern coast was not the only available route for early colonists. An ice-freecorridor formed after 2 ice sheets that had met in the middle of the continentbegan to melt. At first, the meltwater formed vast lakes, but these eventuallydrained, leaving dry land. This corridor ran along the eastern flank of theRockies, from Alaska to the lower 48 states. It was originally believed to haveopened up 13,000 years ago, which fit the Clovis-First scenario, but ruled outit being available for earlier people.
A group ofscientists decided to take another look at this corridor, using new methods ofdating, and determined that the corridor formed at least 14,000 to 15,000 yearsago, possibly more. What's more, the corridor in northern Alberta was at least400 kilometers wide and no longer held any large lakes. Now, the corridor wasscoured by retreating ice and pierced by cold winds, so it would have seemed aformidable place to early travelers. But hunter-gatherers from Beringia mayhave decided to explore it after watching flocks of waterfowl head south in thefall and return in the spring. Food would have been scarce, but the explorerscould have hunted birds or larger game, such as mountain sheep, now believed tohave grazed in the Yukon and northern British Columbia.
Thetravelers may have taken along dogs. Siberian hunters first domesticated wolvesas long ago as 33,000 years. These would have made valuable hunting companionsand pack animals. A 1994 study revealed that dogs carrying 13 kilograms (28.7lbs) could travel as far as 27 kilometers a day, in the right conditions. Ifhunting failed, and starvation threatened, the migrants could have eaten someof their dogs. One scientist calculated the colonists could have reached thesouthern end of the corridor in only four months, traveling at 16 kilometers aday.
Back atButtermilk Creek in Texas, the scientists are still studying the tiny, delicatetools created and left by the pre-Clovis people, and may have found new cluesabout the origins of the Clovis people. 2,500 years after the pre-Clovis peopleknapped blades and bifaces, Clovis hunters used similar techniques across NorthAmerica to make massive, elongated blades, some reaching 21 cm (8.3 inches) ormore in length. It is possible the Clovis people were descended from earliermigrants coming through Beringia.
