It's important to note that Coast Miwok is not a single language, but rather a group of closely related dialects. These dialects were spoken by different Coast Miwok groups throughout the area they inhabited, which stretched along the coast of California from Bodega Bay to the Golden Gate Bridge.
Sadly, Coast Miwok is now extinct. The last fluent speaker, Mary Jemison, passed away in 1967.
Despite its extinction, efforts are underway to revitalize Coast Miwok. The University of California, Berkeley has a Coast Miwok language archive, and there are ongoing projects to document and teach the language to future generations.