GEOSCIENCE ASPECTS OF BLOOD RUN NATIONAL HISTORIC LANDMARK (NHL), IOWA AND SOUTH DAKOTA

Geoscience aspects of Blood Run NHL in northwestern Iowa (IA) and southeastern South Dakota (SD) span a scale spectrum ranging from regional watersheds down to individual ceremonial and burial mounds. The Oneota settlement at Blood Run (1500-1700) participated in a far-flung exchange network by exporting catlinite for pipestone quarried about 50 mi (80 km) from the settlement and by importing other distinctive lithic materials including a green orthoquartzite from the Bijou Hills of central South Dakota more than 150 mi (240 km) away. Major drainages such as the Mississippi and Missouri Rivers guided routes of trade and migration. One particular tributary to the Missouri hosted the Blood Run village complex.

The five individual village sites identified within the Blood Run NHL each have a distinctive geomorphic setting. Three main villages in the core, straddle the Big Sioux River at the mouth of Blood Run Creek. One is located on the steep hills of a glacial end moraine on the west (SD) side of the river. On the east side (IA), two villages are on a high terrace level separated by the creek. Outlying villages to the north and south in Iowa occupy a lower terrace and possibly the Big Sioux floodplain.

At a more detailed level within the main mound group, internal patterns of dwelling sites and mounds may represent discrete neighborhoods. These postulated neighborhoods have expression in the size and erosion rates documented by the mapping of mounds in the nineteenth and twentieth centuries. Further delineation is provided by distinctive patterns in surface collections of artifacts done on the mounds in the 1980s. Specifically, the suggested neighborhoods show differences in total artifact numbers for each mound location, in the ratio of pottery sherds to bone and shell fragments, and in the percentage of Bijou Hills Orthoquartzite in the assemblage of lithic materials.