Wappo is a language isolate (a language unrelated to any other known living language) spoken in central California. Some linguists have suggested it may be
related to Yuki. Language loss has been especially
severe in California, where enslavement and violence against Indian peoples were not actively discouraged, and today only a few elders still speak the
Wappo language, although some younger Wappos are working to revive its use.
Wikipedia: Wappo:
Encyclopedia articles on the Wappo language.
Lenguas Yukian:
Information on the Yuki and Wappo languages in Spanish.
Wappos:
Wappo links.