The Numic Comparative Lexicon is a cooperative effort among four specialists to build a computerized data base for the seven languages of the Numic branch of the Uto-Aztecan language family and to make a new and definitive reconstruction of Proto-Numic. Bands speaking Numic languages lived in every western state in the United States, except for Washington, and in early postcontact times ranged as far north as Alberta and Saskatchewan. One band also occupied a large area in the South Plains. A complete reconstruction of these languages is therefore an important link in the understanding of the prehistory of the western United States. In addition to internal relationships, the Numic languages also had extensive contact with neighboring groups speaking unrelated languages. A complete data base of the Numic languages will aid in the identification of borrowings in other languages and further clarify the history of the region surrounding the Great Basin. The project brings together all known lexicons and vocabularies using commercially available software on a Power Macintosh 7100 computer. This makes possible not only detailed cross-linguistic comparisons, but also comprehensive historical analyses and wide-ranging dialect studies. The data base is designed for efficiency and flexibility of data handling. After gathering all the data in a single location, a larger and more reliable body of reconstructed Proto-Numic forms and cognate sets will be ready for incorporation into Uto-Aztecan cognate sets than has heretofore been available. The use of commercially available software with compatible Macintosh and IBM versions will make the computerized data base readily available to as broad a spectrum of scholars as possible. In addition, the data base will be available for use to supplement tribal literacy courses throughout the Numic area. The number of speakers of Numic languages ranges from fewer than 10 (for Kawaiisu and Panamint) to more than 500 (for Southern Paiute). The vast majority of the speakers listed above are over 50 years of age. This state of affairs makes the compilation of a thorough comparative dictionary of the Numic languages quite pressing while there are still speakers who command their languages and can provide information where data are lacking in currently available sources.