Technical Abstract: Renewed interest in cotton (Gossypium hirsutum L.) production in the Ogallala Aquifer Region can be linked to development of early maturing varieties, rising energy costs, and declining water levels in the Ogallala Aquifer. In this study, the heat unit based, county-wide exceedance probability curves for potential cotton yield were developed using a long term temperature dataset (1971-2000), and counties that have the potential to produce cotton at 1-year and 2-year return periods were mapped. Results indicate that 105 of 131 counties in the study area have the potential to produce cotton with lint yield more than 500 kg/ha at least once every two years. A county-wide yield goal based on a 2-year return period may improve the chances for better profits to producers than with a 1-year return period. However, management uncertainties on fertilizer and pest management and planting and harvesting schedule may require further consideration for estimating potential cotton yield. Nevertheless, these results show that cotton is a suitable alternative crop for most counties in southwest Kansas and all counties in the Texas and Oklahoma Panhandles. Also, a significant reduction in water withdrawals from the Ogallala Aquifer for irrigation is possible if producers were to convert 50 percent of their corn acreage to cotton production.