 About 1647, he repeated the trip, obtained guides, and visited a 'Tsetsen Khan' near Ulan Bator.In 1648, Ivan Galkin built an "ostrog "on the Barguzin River which became a center for eastward expansion.In 1652, Vasily Kolesnikov reported from Barguzin that one could reach the Amur country by following the Selenga, Uda, and Khilok Rivers to the future sites of Chita and Nerchinsk.