Pre-contact distribution of Plateau Penutian languages
Plateau Penutian (also Shahapwailutan, Lepitan) is a family of languages spoken in northern California, reaching through central-western Oregon to northern Washington and central-northern Idaho.
Plateau Penutian consists of four languages:
Plateau Penutian as originally proposed was one branch of the hypothetical Penutian phylum as proposed by Edward Sapir. The original proposal also included Cayuse (which was grouped with Molala into a Waiilatpuan branch); however, this language has little documentation and that which is documented is inadequately recorded. Thus, the status of Cayuse within Penutian (or any other genealogical relation for that matter) may very well forever remain unclassified.
The Sahaptian grouping of Sahaptin and Nez Percé has long been uncontroversial. Several linguists have published mounting evidence in support of a connection between Klamath (a.k.a. Klamath-Modoc) and Sahaptian. Howard Berman provides rather convincing evidence to include Molala within Plateau Penutian. Recent appraisals of the Penutian hypothesis find Plateau Penutian to be "well supported" by specialists (DeLancey & Golla (1997: 181); Campbell 1997), with DeLancey & Golla (1997: 180) cautiously stating "while all subgroupings at this stage of Penutian research must be considered provisional, several linkages show considerable promise" (Campbell 1997 likewise mentions similar caveats). Other researchers have pointed out promising similarities between Plateau Penutian and the Maiduan family, although this proposal is still not completely demonstrated. A connection with Uto-Aztecan has also been suggested (Rude 2000).
The coherence of Plateau Penutian is also supposed in an automated computational analysis (ASJP 4) by Müller et al. (2013). The analysis also found Algic lexical influence on the Plateau Penutian languages.