Biomass is receiving increasing attention as scientists, policy makers, and growers search for clean, renewable energy alternatives. Compared with other renewable resources, biomass is very flexible it can be used as fuel for direct combustion, gasified, used in combined heat and power technologies, or biochemical conversions. Due to the wide range of feedstocks, biomass has a broad geographic distribution, in some cases offering a least-cost and near-term alternative. The objective of this research is to estimate the biomass resources available in the United States and map the results. To accomplish this objective, biomass feedstock data are analyzed both statistically and graphically using geographic information systems (GIS). A GIS is a computer-based information system used to create, manipulate, and analyze geographic information, allowing us to visualize relationships, patterns, or trends that are not possible to see with traditional charts, graphs, and spreadsheets. While other biomass resource assessments concentrate on the economic or theoretical availability, this study estimates the technical biomass resources available in the United States (page 59). The estimates are based on numerous assumptions, methodologies adopted from other studies, and factors that relate population to the amount of post-consumer residue generation. The main contribution of this research is that it adds a geographic perspective to biomass research by answering questions such as where the resources are and how much is available.