The linguist Harvey Pitkin has worked on several of the indigenous languages of Northern California, with a particular interest in Wintu, Patwin, and Yuki. A student of A. L. Kroeber, Pitkin was a member of the Department of Linguistics at the University of California, Berkeley, and later at Columbia University before his retirement in the late 1980s. The Pitkin Papers contain materials recorded or accumuluted by Harvey Pitkin during the course of his study of American Indian languages, including not only his own fieldnotes and research on Wintu and Yuki, but originals and copies of notes, notebooks, and slipfiles by A. L. Kroeber, A. M. Halpern, John P. Harrington, John Alden Mason, Paul Radin, Hans Uldall, Donald Ultan, T. T. Waterman, and others. These include important information on Atsugewi, Kwakiutl, Luiseno, Pomo, Wappo, Yahi, and Yana, and include some data on the consultants Ralph Moore (Yuki) and Ishi (Yahi).

The Jane M. Rosenthal papers contain a wide variety of historical and contemporary audio recordings, texts, elicitations and grammatical descriptions of Nahuatl, particularly the variety spoken in Tlaxcala, Mexico, both from the research of Rosenthal and others. Fieldwork in Tlaxcala (including photographs), archival research in Mexico and Chicago, and the work of many scholars that formed the Friends of Uto-Aztecan are represented.

The William O. Bright papers consist particularly of extensive correspondence relating mostly to his later academic work, a number of field notebooks from North America and India, publications on and by Indigenous North Americans (especially Karuk and other Californian tribes) and from linguistic societies, his own research and publications, and extensive lexical slip files (especially on Karuk, Spanish borrowings, and copies of Daythal Kendall's Takelma and Kalapuyan files). Many audio recordings are also present, some of which are duplicates of those at the California Language Archive. In addition to the materials browsable through the finding aid, Bright's email correspondence and computer files can be accessed onsite at the APS. William Bright's career extended to a wide variety of linguistic work, including Native Californian languages and literatures, Native American place names, editorships of major linguistics journals, and writing systems of the world.

The Mary Rosamond Haas papers are extensive, including correspondence, research notes, field notes, texts, lexical slip files, audio recordings, photographs, reprints and more, covering more than 100 languages of North America and Southeast Asia. Of particular value are notes and audio recordings from fieldwork from the 1930s on Ditidaht, Tunica, Natchez and Muscogee, work toward pedagogical materials for Thai, and groundbreaking comparative studies of several language families of North America.