The response of U.S. soybean export basis (Gulf and Pacific Northwest) to changes in supply and demand (domestic and international), transportation costs, logistics conditions, and export activity variables was examined from both a market-year average and seasonal analog perspective. The market-year average results indicated that basis at both locations were highly correlated and influenced primarily by international and domestic competition. The seasonal analog results indicated a wide variation in seasonality across marketing years for both locations with transportation costs, logistic conditions, and export activity having the greatest influence on the seasonal analog grouping.