Via Uncle Jazzbeau, a nice site for learning Inezeño Chumash. Unfortunately, there’s only a small core vocabulary for the first eight lessons (plus, oddly, a tiny portion of a larger lexicon), but the lessons look well done, and there are sound clips of everything (so that Jim was able to hear the glottalized consonants he had been searching for). Chumash has been extinct since 1965; as the Chumash languages page says:
A great deal of what we know about the Chumash language spoken in the Santa Ynez valley comes to us as a result of the patience and dedication of Maria Solares. Maria was born in the 1840s and died in 1923.
Between approximately 1912 and 1919, Maria worked with John P. Harrington, a linguist who dedicated himself to recording as much as he could of the native languages of California, Chumash as well as many others.
Maria provided Harrington with a wealth of information on the language, beliefs, culture and customs of the Inezeño and their neighbors. Harrington was gifted with an extraordinarily keen ear for language and he recorded what Maria told him in meticulous detail.