Ivanov (Gubar), Postnik (?–?)
Ivanov (Gubar), Postnik (?–?) – a Yenisey Cossack and pathfinder and one of the people to discover Verkhoyansk and Chersky Range. In 1632–1633, he visited a tributary of the Nizhniy Vilyuy River and the lower reach of the Lena River. Leading a team in 1637–1638, he was the first Russian to transverse the central part of the Verkhoyansk Range, the Yana Plateau, and the chain of the Chersky Mountains to the Indigirka cutting main overland route from the Lena River to the middle Indigirka. He brought the first records about the Eveny and the upper Indigirka. In 1639–1640, I. P. managed the Indigirka land and undertook two more expeditions there.