The agricultural landscapes of the Great Plains reflect a complex pattern of soil climate regimes (Soil Taxonomy, Soil Survey Staff, 1999) and inherent variability that influence the cropping systems and behavior of farmers. The historical crop yields and acreage harvested of crops were compared with climatic events through time to describe the trends and adaptations of farmers and changes in agroecology. The USDA National Agricultural Statistics Service and Risk Management Agency's county-level databases were coupled with soil climate regimes derived from the Enhanced Newhall Simulation Model to explain spatial relationships of crop yields and identifying growing environments favorable to corn, soybeans, sorghum, and wheat. In addition, these geospatial databases can be used to characterize shifts in growing environments through time and space. Comparisons were generated at the county level between irrigated and nonirrigated yields, yield ratios (corn:soybeans) to identify favored environments, shifts in crop acreages reflecting past climatic events and changes in genetics, and dominant "cause-of-loss" processes for specific crops. The Enhanced Newhall Simulation Model was used to derive probabilities of soil climate regimes and differentiate agroecological zones. This study also addresses the changes in the agroecology and behavior of soil climate regimes in the Great Plains and connections to El Nino/La Nina events.