The Frank G. Speck Papers consist of field notes, correspondence, lecture notes, printed sources, photographs, drawings, ephemera, and manuscripts of published and unpublished works. The material is primarily focused on Speck's extensive fieldwork with the Native American peoples of the Eastern Woodlands. The original assemblage of the materials in file folders and notebooks has been preserved wherever possible. The collection has been divided into three series.

Series I. Research Materials consists of two subseries. Subseries A. Tribes includes field notes, sources, maps, photographs/negatives, drawings, ephemera, and correspondence from tribal members and informants, and has been organized alphabetically according to tribal affiliation to the best extent possible. Tribes with a greater volume of research material have been categorized separately, and tribes with fewer materials have been included in the subsection "Other Tribes." Due to the nature of the field, there is some overlap in the material with regard to tribe, particularly between tribes that share the same language family, territory, or cultural traits. These intersections in the research material are also a reflection of Speck's method of study, as he often worked with more than one tribal group at a time. Further to Speck's process in the field, much of the information in this series is written down or drawn on small scraps of paper, on the backs of printed pages, in notebooks and in small notations on maps. Some photographs included in this subseries have been classified as culturally sensitive and restrictions on reproduction have been applied to these materials. Citations and copies of excerpts from secondary sources related to specific tribes and Speck's area of interest are also included in this research material. Subseries B. Other Research Material consists of material that is not directly related to Speck's fieldwork with tribal groups. Included are notes and drawing studies of Native American collections from North American and European museums, likely done by Speck's colleague, Marius Barbeau, and notes, citations and sources, guidebooks, draft manuscript pages, and correspondence related to Speck's natural history, general arts, and anthropological research.

Series II. Writings and Publications consists of four subseries. Subseries A. Published Manuscripts includes manuscripts of published works. The papers in this collection include brief citations, excerpts, and drafts with written notations and pages that have been cut and pasted. The title with the greatest volume, Midwinter Rites of the Cayuga Longhouse, has been categorized separately and organized according to chapter. Some photographs included in this title have been classified as culturally sensitive and restrictions on reproduction have been applied to these materials. All other manuscripts of published works that are lesser in volume have been included in the subsection "Other Published Manuscripts" and have been organized chronologically. Subseries B. Unpublished Manuscripts includes manuscripts of unpublished works and related research material. The titles with the greatest volume have been categorized separately. Two works in this collection include authors additional to Speck. The first is a manuscript titled Art and Art Ways of the Naskapi Indian co-authored by Speck and his colleague, Ernest S. Dodge, former director of the Peabody Essex Museum in Salem, Massachusetts. This manuscript includes a letter from Birket-Smith to Speck, anlong with notes by "W.N.F." The second is titled Naskapi Art, which was written by scholar Alika Podolinsky Webber, and includes excerpts from Speck and Dodge's unpublished manuscript, Art and Art Ways of the Naskapi Indian. All other manuscripts of unpublished works that are lesser in volume have been included in the sub-subseries, "Other Unpublished Manuscripts" and have been organized chronologically.

Subseries C. Lecture Notes and Materials includes Speck's typed and handwritten lecture notes, teaching materials and related sources on Indigenous peoples, linguistics, ethnology, and archaeology. Subseries D. Publications includes printed publications written by Speck.

Series III. Personal consists of papers not related to research or writings. Subseries A. Professional Correspondence includes letters to Speck from colleagues, scholars, museum professionals and collectors. Subseries B. Accounts contains financial records, including expenses from individual research trips. Subseries C. Other includes newspaper clippings, a brochure, and a pamphlet.