This multimedia language resource is being created from a 19th century unpublished Omaha/Ponca word list collected by James Owen Dorsey (1848-1895). The original slip file housed in the National Anthropological Archives at the Smithsonian Institution was microfilmed by the Project Director in 1988. The estimated 20,000 images have now been digitized by the Center for Digital Research in the Humanities at the University of Nebraska–Lincoln Libraries. The information from each slip is being entered into a database where it is organized and undergoes linguistic analysis. The on-line dictionary emerges from the database. The Dorsey slip file represents an important collection of Omaha language, and the culture it transmits, from an historic perspective. The purpose of the OPDD project is to bring this 19th century collection to light and present it in a way that is accessible and useable for people interested in the Omaha and Ponca languages. The database and its on-line dictionary component are designed for future growth with the addition of contemporary language annotations, images, audio files, and text. The compilers of this dictionary web site are solely responsible for its contents.