In Siberia Jochelson made a special study of the language, manners, and folk-lore of the aboriginal inhabitants, especially that of the Tungus, Yakuts, and the fast-disappearing Yukaghirs. His articles on those subjects began to attract attention, and in 1894 he and a fellow exile, Vladimir Bogoraz ("Tan", also of Jewish descent), were by special permission attached to the first expedition of the Imperial Russian Geographical Society (1894–97), which had been sent to that part of Siberia at the expense of a wealthy Russian promoter of art and science named Sibiryakov.
In Siberia Jochelson focused on studying the language, customs, and folklore of the indigenous populations, particularly those of the Tungus, Yakuts, and the rapidly disappearing Yukaghirs. His writings on these subjects started to gain recognition, resulting in his collaboration with fellow exile Vladimir Bogoraz ("Tan") on the Imperial Russian Geographical Society's expedition (1894–97), supported by a wealthy patron named Sibiryakov.