The U.S. hog industry is experiencing increases in both the average size and geographical concentration of feeding operations. These increases have focused attention on the environmental consequences of hog production and on the regulations imposed to limit these consequences. This study examines the effect that differences in state water quality regulations have on the location of hog production. The analysis is conducted separately for large and small farms. Results suggest that the current trend of increasing environmental regulation does not have a significant impact on the location of hog production.