Shock of footprints in White Sands. First Americans weren’t mammoth hunters, but sea tribe like Hokkaido Sojin, Proto-Japanese, not Ainu since 13th century. And important thing is that Ice sheet should be moderate along sea shore where no islands existed in southern Alaska area. Migration happened in relatively warmer era before Last Glacial Maximum. It means there wasn’t Beringia, but Bering strait was seen.