This paper begins with a discussion concerning the development of the term "atlatl weight" in archaeological literature. It then proceeds to analyze in detail data relative to 60 atlatl weights from 39 locations on the Plains area of Alberta, Saskatchewan, Montana, Wyoming, Colorado, North Dakota, South Dakota, Nebraska, Kansas, and Iowa. Although most of the specimens are surface finds, a number are from systematically excavated, radiocarbon-dated occupations.
Differentiated primarily on their general shapes, five groups of atlatl weights seem apparent: Class I, loaf-shaped; Class II, end-ridged; Class III, long ellipsoidal; Class IV, zoomorphic; and a miscellaneous category.
Available evidence suggests that atlatl weights were being made, in the area under consideration, from about 2500 B.C. until A.D. 800.