In Siberia, there are many ancient cities, and one of the largest, such as Chita, Yakutsk, and Nerchinsk, owes its existence to the shooter Petr Ivanovich Beketov. In 1628, he voluntarily submitted a request for transfer to the Yenisei ostrog. From the first months of service, he was entrusted with important tasks, including negotiations with the Tungus. Local residents often attacked Russian settlements, burning houses, looting, and taking people captive. However, Petr Ivanovich, guided by humanitarian considerations, did not respond to violence with violence. He convinced the Tungus that the Russians came in peace and did not wish to harm the indigenous people. As a result, the raids ceased for a long time.

A few years later, Beketov received a new assignment to establish a presence on the banks of the Lena. At that time, only trade routes were known, but there were no permanent settlements here. Petr Ivanovich, along with the Cossacks, built a small ostrog, which eventually turned into the city of Yakutsk. Thus began the development of the adjacent valleys, and the Russians gradually moved towards the Pacific Ocean. As the voivode in the new ostrog, Beketov spent a year and returned with a rich haul: he acquired almost 800 sable pelts and 135 foxes for the treasury, spending only 111 rubles on this. In Yeniseisk, such furs cost 1240 talers.

However, Petr Ivanovich's travels in Siberia did not end there. In 1652, he set out on a campaign to Transbaikalia. The advance was extremely difficult; the Cossacks often starved and subsisted on roots and herbs. Nevertheless, they found a suitable place to build an ostrog at the confluence of the Ingoda and Chita rivers. Thus, another important Russian outpost in Siberia was established. It is worth noting that the route taken by Beketov later became part of the Siberian tract, and Petr Ivanovich himself became a significant figure in the history of these places. It is no wonder that the exiled theologian Yuri Krizhanich wrote with admiration about his meeting with Beketov: 'I personally saw the one who first erected a fortress on the banks of the Lena.'