The first record over the period of study of the local fauna of snakes of the genus Gloydius in the Republic of Sakha (Yakutia) is described. We analyzed the literature data as well as the records of pit vipers confirmed by voucher specimens and photographs from the territory east of Lake Baikal — in the Far East of the Russian Federation (Primorskyi Krai, Khabarovsk Krai, and Amur Oblast, Sakhalin Oblast and Chita Oblast). Earlier the first reliable record of snakes of the genus Gloydius ( G. ussuriensis ) in the north of the Chita Oblast on the Ingoda River (Orlov et al., 2014; ZISP 28004 — 28008) was discovered. The first records of G. halys in the Lena River basin and its tributary Olekma River on the territory of the Republic of Sakha (Yakutia) are described in this paper. These data principally change existing ideas about the distribution of snakes in East Asia.