A culture in existence approximately 12,000 years ago between Siberia and temperate Alaska. The term was used by H. West to cover various Alaskan and Siberian archaeological formations which had developed from the Siberian Upper Paleolithic period, an area now largely submerged under the Bering Strait. Chronologically these formations lie between the middle of the Holocene period (c 35,000-9/10,000 BP), depending on the area. West's categorization includes the Bel'kachi, Diuktai, and Lake Ushki cultures in Siberia, the Denalian culture and American Paleo-Arctic formations in Alaska and the Yukon. Although Alaska is generally thought to be the gateway through which humans entered the New World, the earliest undisputed evidence for people there dates later than 12,000 years ago, well after the climax of the last major glacial advance but while glaciers still covered much of Arctic Canada. Artifacts of 11,500 to 9,000 years ago are known from a number of Alaskan sites, where hunters of caribou (and, in one case, of an extinct form of bison) manufactured blades.