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In late autumn of the year 1995, trudging alone over ice- and snow-covered hills and plains, I walked into the Crow Valley (wuya gu) in mountainous western Colorado and examined the sites of ancient American Indian tribes. Local archaeologists had told me the Indians living here had migrated from North China and Northeast China nine thousand years ago. I returned from the mountains that evening and made my way to a wooden cabin for archaeologists, built in a col. I planned to have supper there. To my surprise the little dining room, which normally was occupied only by myself and two undergraduate archaeologists, was packed with youngsters.
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Xiguang Li (1998) studied this question.
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