Distinct types of grooved stone mauls are so common in the northwest prairie states that they deserve a brief description.

South Dakota appears to be about the center of the area in which they are found. They are common in North Dakota and the southwest corner of Minnesota, the northwestern part of Iowa, Nebraska, and the eastern parts of Wyoming and Montana. Those found outside of the above area were probably exchange pieces traded with neighboring tribes. These stone mauls seem to be as common in the northwest prairie states as the grooved stone ax is in the woodland region southeastward. In the earlier days they were commonly used as door stops in the cabins of the pioneers; farmers fastened two together with rope or wire and used them as windbreaks on hay and grain stacks. Every private collection contains several, and nearly four hundred have accumulated in the University of South Dakota Museum without special effort to collect them.