Central Texas was probably covered by tall grass prairie , with pine and aspen growing in the river bottoms. The high plains of west Texas were most likely covered by short grass prairie and semidesert. These prairies were probably similar to those of the present day Canadian Provinces of Saskatchewan and eastern Alberta. The harshest climatic conditions occurred in a zone adjacent to the ice edge. Cold temperatures and strong winds, due to the proximity of the ice, created an Arctic desert , devoid of virtually all plants and littered with rock debris and fine-grained sediment deposited by the galcial meltwaters.
Loess deposits cover much of the Midwest and extended south into Louisiana and Mississippi.
Animals moved north and south with the vegetation zones. Several theories have been proposed to explain why these animals became extinct .