Ust-Kut is a town and the administrative center of Ust-Kutsky District in Irkutsk Oblast, Russia, located 961 kilometers from Irkutsk, the admiā¦Ust-Kut is a town and the administrative center of Ust-Kutsky District in Irkutsk Oblast, Russia, located 961 kilometers from Irkutsk, the administrative center of the oblast. Located on a western loop of the Lena River, the town spreads out for over 20 kilometers along the left bank, near the point where the Kuta River joins from the west. Population: 45,375 ; 49,951 ; 61,165.