The one of last fluent speaker of Rumsen was Isabel Meadows, who died in 1939. The Bureau of American Ethnology linguist John Peabody Harrington conducted very extensive fieldwork with Meadows in the last several years of her life. These notes, still mostly unpublished, now constitute the foundation for current linguistic research and revitalization efforts on the Rumsen language. The Costanoan Rumsen Carmel Tribe has been in the process of reestablishing their language. They have begun efforts to teach their tribal members Rumsen and are working to complete a revised English - Rumsen Dictionary. The Rumsen website can be found at www.costanoanrumsen.org.
Dialects of the Rumsen language were spoken by four independent local tribes, including the Rumsen themselves, the Ensen of the Salinas vicinity, the Calendaruc of the central shoreline of Monterey Bay, and the Sargentaruc of the Big Sur Coast. The territory of the language group was bordered by Monterey Bay and the Pacific Ocean to the west, the Awaswas Ohlone to the north, the Mutsun Ohlone to the east, the Chalon Ohlone on the south east, and the Esselen to the south.
Kroeber, Alfred L. 1925. Handbook of the Indians of California. Washington, D.C: Bureau of American Ethnology Bulletin No. 78. (map of villages, page 465)
Levy, Richard. 1978. Costanoan, in Handbook of North American Indians, Vol. 8 (California). William C. Sturtevant, and Robert F. Heizer, eds. Washington, DC: Smithsonian Institution, 1978. ISBN 0-16-004578-9 / 0160045754, pages 485-495.
Milliken, Randall. 1987. Ethnohistory of the Rumsen. Papers in Northern California Anthropology No. 2. Salinas, CA: Coyote Press.
Teixeira, Lauren. The Costanoan/Ohlone Indians of the San Francisco and Monterey Bay Area, A Research Guide. Menlo Park, CA: Ballena Press Publication, 1997. ISBN 0-87919-141-4.