Lyle Campbell (1997) considered the proposed Takelma-Kalapuyan hypothesis "highly likely, if not fully demonstrated", and listed them as a single subgroup in an overview of Native American language families that is otherwise characterized by a very critical stance against wide-range proposals. Takelma-Kalapuyan is also tentatively accepted by
Victor Golla (2011). In an unpublished, but widely cited conference paper, Tarpent and Kendall (1998) critically evaluated the evidence for Takelma-Kalapuyan, and concluded that a grouping which exclusively comprises Takelma and Kalapuyan is not justified, and that features shared between the two have to be assessed in a wider Penutian context (a similar position was taken before by Silverstein (1979)).
Marianne Mithun (1999) accepts Tarpent and Kendall's findings, but remains sceptical about the validity of the Penutian hypothesis, and therefore lists Takelma as a
language isolate and Kalapuyan as a primary language family. Grant (2002) maintains that even though the relation between Takelma and Kalapuyan is not as close as previously assumed, Tarpent and Kendall's discussion does not invalidate the hypothesis that Takelma and Kalapuyan are "each other's closest genetic relatives", albeit only at an extremely distant level. ==Prehistory==