Over the past 400 to 500 years, the Great Plains have seen a rapid succession of ecological regimes. The ecological historian Dan Flores has written that plains ecological history "centers around a series of ecological crashes and simplifications."1 This text attempts to give an overview of these successive ecological systems and to provide an analysis of the lessons in sustainability, resilience, and ideology offered by plains ecological history of the past few centuries. The plains, a semi-arid ecosystem, have "fewer of the safeguards built into more diverse systems."2 Because natural resources "in semi-arid countries are often set in a hair-trigger equilibrium,"3 the plains can serve as a good model for issues of sustainability and resilience elsewhere. Many historical and ethnographic studies have looked at human-bison interactions, hunter-gatherer lifeways, and Native agriculture on the plains. Agricultural, wildlife management, and grasslands research have both led to and engaged with the industrial ecosystems that has become imposed in the plains. Ecological approaches have also been used to discuss sociological consequences and political proposals for this vast region. This is not a detailed study, and I can do no justice to the broad literature: my focus will be on what the plains can teach us about sustainability.