Co-authored by pioneering anthropologists Leo Joachim Frachtenberg and Franz Boas, Coos, an Illustrative Sketch provides a rigorous, structural analysis of the severely endangered Hanis Coos language native to the southern Oregon coast. Published as part of Boas’s monumental initiative to map North American Indigenous linguistics, the text meticulously breaks down the complex phonology, morphology, and syntactic architecture of a tribal language heavily decimated by forced relocation and settler encroachment. By formally diagramming these intricate grammatical rules directly from the region's last fluent speakers, the authors produced a vital ethnographic artifact that preserved the mechanical brilliance of coastal oral traditions. A keen insight drawn from the work is how the rigorous application of Boasian linguistics functioned as a subtle but powerful critique of pioneer-era racial hierarchies; by scientifically demonstrating that the Coos language possessed a structural logic and grammatical complexity equal to or surpassing European tongues, the text implicitly dismantled the self-serving settler myth that the region's Indigenous populations were culturally or intellectually primitive.