The documentation consists of a 12-page vocabulary by James Owen Dorsey, three months of fieldwork by Leo J. Frachtenberg in 1911 with a non-English-speaking native speaker and her Alsean husband (who spoke it as a second language), audio recordings of vocabulary by Morris Swadesh in 1953. Frachtenberg (1914, 1922) and Hymes (1966) are publications based on their material.
Dorsey, James Owen. (1884). [Siuslaw vocabulary, with sketch map showing villages, and incomplete key giving village names October 27, 1884]. Smithsonian Institution National Anthropological Archives.[1]
Frachtenberg, Leo Joachim; Franz Boas; Smithsonian Institution. Bureau of American Ethnology (1917). Siuslawan (Lower Umpqua): an illustrative sketch. Govt. Printing Office. Retrieved 28 August 2012.
Frachtenberg, Leo. (1922). Siuslawan (Lower Umpqua). In Handbook of American Indian languages (Vol. 2, pp. 431–629).
Hymes, Dell. (1966). Some points of Siuslaw phonology. International Journal of American Linguistics, 32, 328-342.