1. Introduction. Molala was formerly spoken in the Cascade mountains in west central Oregon. It was bounded by Clackamas Chinook, Northern Kalapuya, Central Kalapuya, Southern Kalapuya, Oregon Athapaskan, Takelma, Klamath, and Sahaptin. It has been extinct since the death of Fred Yelkes, the last known speaker, in 1958. Molala was once thought to be closely related to the poorly attested Cayuse language of northeastern Oregon and southeastern Washington. Powell (1891) placed them together in a family which he called Waiilatpuan, and this was the accepted position among linguists for over seventy years. However, Rigsby (1966; 1969) reexamined the Cayuse and Molala data and concluded that there was not enough evidence to support the relationship. Molala thus stands as a language isolate with no close relatives. Gatschet (1890) compared Klamath with several languages of California and Oregon, including Molala, and concluded that" The Sahaptin and Wayiletpu families are the only ones with whom a distant kinship is not altogether out of the question"(1890: lvi). The Klamath-Sahaptin-Waiilatpuan grouping was included by Sapir (1929) among the families which he considered" either probable or very possible." In his famous six-stock classification in the same article he placed these languages in the Penutian stock and gave them the name" Plateau Penutian." After Gatschet, no evidence was presented for any part of Plateau Penutian until Aoki (1963) published a lexical comparison of Klamath and Sahaptian. Recently, scholars at the University of Oregon have investigated the Klamath-Sahaptian relationship in detail and have published a series of articles giving both lexical and grammatical evidence (Rude 1987, DeLancey, Genetti, and Rude 1988, and DeLancey 1992). However, except for the Molala numerals cited by Aoki (1963) and the occasional Klamath and Sahaptian forms cited by Rigsby (1966; 1969), Molala has been left out of these comparisons. In this article I present evidence to show that Molala is related to Klamath and Sahaptian. I also discuss the possible relationship of Molala and Cayuse, and the possible relationship of Plateau Penutian to California Penutian. 1