Vipera berus sachalinensis (Sakhalin Island adder[2] a.k.a.

Sakhalin adder[3]) is a viper subspecies[4] endemic to Asia.

It is found in the Russian Far East (Amur), China (Jilin), North Korea, and on Sakhalin Island.

[5] According to Schwarz (1936), the type locality is "Sachalin" (= Sakhalin Island, Russia).

[1] However, it has been considered a full species in recent literature.