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.

Audio recordings, primarily linguistic field recordings of Native American languges, removed from the James M. Crawford papers. The bulk of the recordings are in three areas: Alabama songs, stories, and fiddle music; Cocopa folklore, autobiographical stories, songs, and elicited words and sentences; Yuchi autobiographical stories, conversations, and elicitied word lists. Other material includes: Cherokee conversations; Chickasaw word and phrases lists; readings from a Chontal-Spanish dictionary; a Diegueño text; words lists and discussion regarding the Mobilian trade language (Yama); intermixed Mobilian, Choctaw, and Koasati word lists; Mohave songs, with explanations; a Navajo elicitation session, with interview and conversation; elicited Shoshoni expressions; Tolowa songs, Yavapai word lists and texts; and Yuki words and expressions. The small amount of non-Native American material in the collection generally consists of unidentified conversations, readings of English and Russian texts, and recordings of baby talk.