declining health and age and the fact that Cooper had probably not spoken or heard her native language since her childhood, the pair persisted in documenting linguistic and cultural knowledge about the indigenous people who once lived in what is now the area of San Luis Obispo County. Harrington's primary focus as a linguist was the documentation of the Obispeño language and grammatical structure, but through their interviews they were also able to document cultural knowledge pertaining to indigenous material culture, diet and use of native flora and fauna, indigenous beliefs and practices, place names, and songs and dances. Cooper also related stories and experiences from her youth that reflected relationships and people in her life that had been important to her. Material culture From her childhood, Rosario recalled watching her mother and how she started fires using rotating sticks, and made hairbrushes embedded with glass beads to sell. She also described a game played with walnuts filled with brea by Yokuts natives. Diet and use of native flora and fauna Cooper also talked about traditional plant foods gathered and prepared by the native women in her life, such as islay and acorns. Given the proximity to the California coast, Rosario also reported indigenous uses of marine foods, such as collecting clams at Avila Beach and using sea urchins for food and medicinal purposes. Indigenous spirituality and practices During the interviews, Cooper told Harrington about indigenous uses and fears of spiritual practices, which, she reported, had resulted in the death of several of her half-siblings. Cooper also told Harrington a story about the time her own mother had been bewitched, and had then sought out the help of a medicine-man, who used techniques such as fasting, singing, and blood-letting to cure her. Though Spanish introduction of Catholicism across California interrupted some native beliefs, Cooper said that the Chumash believed in the sun, moon, stars, Bear, and Coyote. Cooper also had recollections of older Chumash women offering sacrifices off the coast to marine animals such as dolphins and swordfish. Place names Cooper also related to Harrington the place name of tstʸɨwɨ, which was later used to identify the archaeological site at Pecho Creek. In 2015, an archaeological investigation was conducted by California Polytechnic State University, observed by Cooper's great-great-granddaughter, which revealed archaeological findings that gave important insight into how the indigenous lifestyles changed from pre-contact to post-contact times. Songs and dances