The first Kamchatka expedition of Vitus Bering (1681-1741) headed from St. Petersburg through Siberia to Okhotsk in the winter of 1725, and the following autumn the advance party arrived in Okhotsk ostrog. After waiting for all the personnel, in the spring of 1727, the Bering expedition moved further from Okhotsk to explore the Far Eastern shores of the Russian Empire, primarily Kamchatka, and returned to the fortress in July 1729.
In 1775, merchant-entrepreneur, future explorer Grigory Ivanovich Shelekhov (in some sources the surname was indicated as Shelikhov) (1747-1795) moved from Irkutsk to Okhotsk. In August 1783, his expedition consisting of about 200 sailors who agreed to settle on new lands left Okhotsk Ostrog to the shores of North America. Shelekhov returned in early 1787.