In earth-diver creation myths, earth-making material must be brought up from the depths of the primordial waters—literally, the birth waters of earth. Usually an animal—but sometimes a god or a hero—is sent to retrieve the necessary substance. Earth-diver creations are prevalent especially among the eastern tribes of North America, such as the Iroquoian peoples. As Native Americans almost certainly originally crossed into America via the Bering Strait land bridge, it is not surprising that earth-diver creations are ubiquitous in Asia, particularly in Central Asia. Native Americans add an interesting element to the archetype, however. The earth-diver act itself is preceded in many American earth-diver myths by the motif of the woman who falls from the sky and becomes the sacrificial world parent. The Oneida of New York State are members of the Iroquois Federation, and as do the other Iroquois, they tell the story of Sky Woman.