Pathfinders – Russian trades or service class men, whose activities lead them to geographic discovery of North and Northeast Asia, of the seas washing it and initiated its reclamation. They were the first to travel through the whole of Siberia from the Urals to the Pacific Ocean in around 60 years, from the end of the sixteenth to the middle of the seventeenth century. The starting point for all the trips to the shores of the Bering Strait and the northern part of the Sea of Okhotsk was the lower reaches of the Kolyma River. They also made use of the sea route from the Lena mouth to the mouths of the Yana, Indigirka, Alazeya, and Kolyma. In order to get access to the Pacific Ocean from the Lena in the seventeenth century, the Ps. also used the rivers Uda, Ulya, and Okhota, flowing into the Sea of Okhotsk. In the second half of the seventeenth century, the Okhota and the Ulya were often reached by means of the rivers Maya (the Aldan tributary) and Yudoma (the Maya tributary).
As a result of steady advance eastward, the Russians reached the coast of the Pacific Ocean as early as the beginning of 1640. In the second quarter of the seventeenth century, they passed all separate parts of the Arctic seas along the Asian coast and the coast of the Sea of Okhotsk. The middle of the seventeenth century was marked by geographic discoveries of great historical importance. Fedot Popov (Alekseev) and Semen Dezhnev navigated around the Chukotka Peninsula through the strait between Asia and America (the Bering Strait); Vassili Poyarkov and Yerofey Khabarov conducted their prominent trips to the Amur. The end of the seventeenth century was marked by the expeditions of Vladimir Atlasov to Kamchatka. By the beginning of the eighteenth century, part of the territory and a huge hydrographical network of Siberia and the Far East were explored, and the navigations of the polar mariners foreshadowed the reclamation of the Northern Sea Route.