In 1867, he was sent to Irkutsk in Siberia, where he began to explore the highlands on the banks of the river Ussuri, a tributary of the Amur.
He was sent to Irkutsk in Siberia. This was in 1867. He began to explore the highlands on the banks of the river Ussuri. The river Ussuri was a tributary of the Amur.