Confluence of Biya and Katun Rivers Forming the Ob River, Russia52.5N 85.2E
The Ob River crosses the upper half of this orthorectified image of western Siberia, Russia. It is the country’s fourth longest river and is famous for having the longest estuary in the world.
Here, the Ob can be observed at its origin: the confluence of the Biya and Katun Rivers, 16 miles (26 km) southwest of Biysk in Altai Krai (the city is visible upon opening the full image).
Both the Biya and the Katun have their origin in the Altai Mountains, visible here in the lower part of the image. The former issues from Lake Teletskoye; the latter, 80 miles (130 km) long, bursts out of a glacier on Mount Byelukha.