Native grasslands and the stabilization of earthwork archaeological sites on the middle Missouri River,North Dakota

Abstract

Site condition and management practices at six Missouri River archaeological sites are reviewed and the condition of the sites compared between observations in 1993 and 1998. Earthwork sites in a cover of prairie or pasture grasses that have been mown for interpretation purposes have become more infested with ground squirrels. Tall prairie or shrubland obscures site features but these animals are less numerous on sites with such cover. One mown site in an urban area had no ground squirrels, suggesting that the animals had been removed by local urban dwellers or their cats and had no chance to re-invade. The long-term stability of archaeological sites can best be achieved by allowing native prairie grasses to grow tall, leaving only small samples of the site area open, or by control of ground squirrel numbers.