The 8km Legal Amazon Mask was generated by Christopher Potter at the Ecosystem Science and Technology Branch / Earth Science Division of NASA Ames (Potter and Brooks-Genovese, 1999). The mask was generated from the Digital Chart of the World (DCW) available from Environmental Systems Research Institute, Inc. (ESRI). The Legal Amazon of Brazil is defined by law to include the states of Acre, Amapa, Amazonas, Para, Rondonia, Roraima, Mato Grosso, Maranhao, and Tocantins (Anuario Estatistico do Brasil, 1991). This is the definition used in generating the Legal Amazon mask. The mask is available in ASCII grid format for ArcInfo or other GIS software. The README file accompanying the mask has more information regarding data format.