With these facts before them, the students of the peopling of this continent were always drawn strongly to Alaska and the opposite parts of Asia; but the distances, the difficulties of communication, and the high costs of exploration in these far-off regions have proven a serious hindrance to actual investigation. As a result, but little direct, systematic, archeological or anthropological (somatological) research has ever been carried out in these regions; though since Bering's, Cook's, and Vancouver's opening voyages to these parts a large amount of general, cultural, and linguistic observations on the natives has accumulated.
For these observations, which are much in need of a compilation and critical analysis, science is indebted to the above-named captains; to the subsequent Russian explorers, and especially to the Russian clerics who were sent to Alaska as missionaries or priests to the natives; to various captains, traders, agents, miners, soldiers, and men in collateral branches of science, who came in contact with the aborigines; to special United States Government exploratory expeditions, with an occasional participation of the Biological Survey and the Smithsonian Institution, such as resulted in the fine "Corwin" reports and the highly valuable accounts of Leffingwell, Dall, Nelson, and Murdoch; to the separate pieces of scientific work by men such as Gordon and Jennes; and to Jochelson and Bogoras of the Jesup exploring expedition of the American Museum.
As a result of all these contributions, it may be said that there has been established a fair cultural and linguistic knowledge of the Aleut, the Eskimo, and the Chukchee, not to speak of the Tlingit, consideration of which seems more naturally to fall with that of the Indians of the northwest coast.
There are also numerous though often very imperfect and occasionally rather contradictory notes on the physical status of these peoples, and some valuable cultural and even skeletal collections were made. Since 1912 we possess also a good series of measurements on the St. Lawrence Island natives, together with valuable cranial material from that locality, made, under the direction of the writer, by Riley D. Moore, at that time aide in the Division of Physical Anthropology in the United States National Museum.