(also Oldo), a river in the Yakut ASSR, a right tributary of the lana. It measures 330 km long and drains an area of 16,100 sq km. Originating on the eastern slope of the Khada-ran’ia Mountains of the Cherskii Range, it flows around the mountains from the north, primarily toward the southwest. It meanders in its middle course. The Ol’dzho is fed by snow and rain. The highway from the Iana River to the Indigirka River runs along the valley of the Ol’dzho.