Possibly the first dissertation written for a linguistics department (a relatively new discipline) was on Hupa (hup), a language spoken in northern California. According to “Home drives — and pulls — a UC Berkeley student” on the Contra Costa Times site, that was in 1903 at the University of California, Berkeley.
While Wikipedia cites the US census in saying there were 64 people between the ages of 5 and 17 who spoke Hupa in 2000, the Ethnologue has eight speakers as of 1998, and a grant description on the HRELP site states there are fewer than five native speakers.
Despite those troubling statistics, there is a new hope for the language: Graduate students at the University of California, Berkeley, are studying Hupa, and their number includes Kayla Carpenter, a Hoopa Valley Tribe member.
One of their projects is a password-protected online dictionary of Hupa, which looks like it will be useful in many ways as can be seen in “An online multimedia dictionary of Hupa (Athabaskan),” a presentation about the project. According to Andrew Garrett’s page at the University of California, Berkeley, graduate students Amy Campbell, Ramón Escamilla, Andrew Garrett, Lindsey Newbold, and Justin Spence are working with Victor Golla to create the resource, not yet available to the public, which is based on Golla’s dictionary, probably referring to the second edition of the Hupa Language Dictionary.
Although some of the links are now old, an excellent resource for Hupa links is Danny Ammon’s Hupa Language Web Site.