Itelmen is spoken by some older speakers on the
west coast of the Kamchatka peninsula, USSR. Volodin
(1976) describes a limited vowel harmony system based on
height, /i,u/ -> /e,o/ and /e/ -> /a/ when a low(er) vowel
follows. Glottal stop is largely found at morpheme
boundaries. Several phonetic descriptions are vague; /a/
may be central or front, the lateral fricatives might not
be actually fricative, the alveolar ejective affricate
might be be palato-alveolar (it is described as
contrasting with /tS/ by being non-palatalized).

Volodin, A.P. 1976. Itel'menskij Jazyk. Nauka,
Leningrad.