Chumashan is an extinct and revitalizing family of languages that were spoken on the southern California coast by Native American Chumash people, from the Coastal plains and valleys of San Luis Obispo to Malibu, neighboring inland and Transverse Ranges valleys and canyons east to bordering the San Joaquin Valley, to three adjacent Channel Islands: San Miguel, Santa Rosa, and Santa Cruz.
The Chumashan languages may be, along with Yukian and perhaps languages of southern Baja California such as Waikuri, one of the oldest language families established in California, before the arrival of speakers of Penutian, Uto-Aztecan, and perhaps even Hokan languages. Chumashan, Yukian, and southern Baja languages are spoken in areas with long-established populations of a distinct physical type. The population in the core Chumashan area has been stable for the past 10,000 years. However, the attested range of Chumashan is recent (within a couple thousand years). There is internal evidence that Obispeño replaced a Hokan language and that Island Chumash mixed with a language very different from Chumashan; the islands were not in contact with the mainland until the introduction of plank canoes in the first millennium AD.
