Volzhskaya, Bratsk, Krasnoyarsk hydroelectric power plants, Dneproges. Geological surveys in the area of the Yenisei River, at the site of the future construction of the Sayan hydroelectric power station. Geologists Yu. I. Prokofiev, V. Baldukhin in the taiga, on the river, by the fire, in a boat, in a helicopter; work at a drilling rig, extracting soil samples from the bottom of the Yenisei River. Workers are working in an adit. Explosion of the rock.