The Stone Age cultures in North America, of the native 'Amerindian' tribes, continued long after the introduction of metals in Europe and other parts of the Old World. Flint and chert arrowheads, for example, were still in use by native Amerindians until the 19th century. Some of the artefacts offered here are from the famous 'Sweetwater Collection', an assemblage of American Indian stone tools dating from the Paleolithic (circa 40,000 B.C. - 12,000 B.C.), Late Paleolithic (circa 15,000 B.C. - 10,000 B.C.), Transitional Paleolithic (12,000 B.C. - 9,000 B.C.), Early Archaic (circa 10,000 B.C. - 7,000 B.C.), Middle Archaic (7,000 B.C. - 4,000 B.C.), Late Archaic (4,000 B.C. - 3,000 B.C.), and Woodland periods (1000 B.C. - 800 A.D.). The materials used in North America include chalcedony, hornstone, petrified wood, quartzite, quartz and chert. The items in that collection were gathered from extensive farmland in Sweetwater County, Wyoming, over a period of about three decades. This area later became the homelands of the Shoshone and Arapaho tribes. Although the basic forms of the artefacts and implements are broadly similar to those from other parts of the world, many North American pieces have distinctive details that make them stand out.