ANNOTATION: Optimal locations for biomass facilities that use mill residues are identified for 13 southern U.S. states. The Biomass Site Assessment Tool (BioSAT) model is used to identify the top 20 locations for 13 southern U.S. states. estimates when compared to demand point location based on a county centroid. The top 20 areas identified in the study region are located in south Mississippi, southeast Georgia, southeast Oklahoma, southwest Alabama, and east Texas. Costs in these areas range from $25 to $38 per dry ton for up to 1.5 million annual dry tons. Additional research on BioSAT is forthcoming for 33 eastern U.S. states. These studies will include more types of woody and agricultural biomass (e.g., logging residues, pulpwood, corn stover, etc.). Additional cost models for transportation such as truck combinations with rail and barge will be components of BioSAT. Annotation: Optimal locations for biomass facilities that use mill residues are identified for 13 southern U.S. states. The Biomass Site Assessment Tool (BioSAT) model is used to identify the top 20 locations for 13 southern U.S. states. estimates when compared to demand point location based on a county centroid. The top 20 areas identified in the study region are located in south Mississippi, southeast Georgia, southeast Oklahoma, southwest Alabama, and east Texas. Costs in these areas range from $25 to $38 per dry ton for up to 1.5 million annual dry tons. Additional research on BioSAT is forthcoming for 33 eastern U.S. states. These studies will include more types of woody and agricultural biomass (e.g., logging residues, pulpwood, corn stover, etc.). Additional cost models for transportation such as truck combinations with rail and barge will be components of BioSAT. ABSTRACT: Optimal locations for biomass facilities that use mill residues are identified for 13 southern U.S. states. The Biomass Site Assessment Tool (BioSAT) model is used to identify the top 20 locations for 13 southern U.S. states. The trucking cost model of BioSAT is used with Timber Mart South 2009 price data to estimate the total cost, average cost, and marginal costs for biomass facilities that use mill residues for up to 1.5 million dry tons of annual consumption. Demand locations are based on the U.S. Census Bureau zip code tabulation areas (ZCTA). There are 9,353 zip code tabulation areas (ZCTA) in the 13-state study region. Demand point location based on a ZCTA offers an improvement in truck cost estimates when compared to demand point location based on a county centroid. The top 20 ZCTAs in the study region are located in south Mississippi, southeast Georgia, southeast Oklahoma, southwest Alabama, and east Texas. Costs in these areas range from $25 to $38 per dry ton for up to 1.5 million annual dry tons.