ABSTRACT This research will result in a compilation of a Rumsen dictionary and material for a future Rumsen grammar. The data base consists of a copy of Prof. William Shipley's slip file, based on a portion of J.P. Harrington's Rumsen field notes, and copies of microfilms of the remainder of those field notes. The Principal Investigator (PI) will direct a post-doctoral Research Associate 2 in the compilation of the dictionary. The Research Associate will have at her disposal a Zenith-100 Personal Computer with a hard disk and an Epson LQ-500 Printer or the equivalent. She will enter the Rumsen words and sentences onto the hard disk in the form of dictionary entries. Principal entries will consist of underlying stems, with derived stems as subentries. Example sentences will be included to illustrate the range of meaning. Affixes will also be included in the dictionary, but their full analysis will await the Rumsen grammar. The Rumsen dictionary will greatly aid the PI in her on- going reconstruction of Proto Costanoan (the original Costanoan language) and Proto Utian (the original Miwok-Costanoan language). The project will also provide extensive data for Amerindianists generally.