The concept of a cultural hiatus, when it is believed the Northern Plains was essentially abandoned by prehistoric bison-hunting cultures because of extremely adverse climatic conditions in the interval 5500-3000 B.C. has become generally entrenched in archaeological thought and literature. However consideration of the current palynological data and climatic models indicate that a grassland environment which supported a viable bison population existed at this time. Examination of the archaeological data indicates the lack of evidence for human occupation is a result of sampling, geological variables and nonrecognition of the artifact types in surface collections. It is concluded that the area supported a viable human population at this time whose primary adaptive strategy centered around the communal hunting of bison.