The Ob' rises in southern Siberia at the junction of the Bija and Katun rivers, just below the town of Bijsk. It winds its way north out of the foothills of the Altai and Sayan Mountains for 700 kilometers until it reaches the largest city along its course, Novosibirsk. There is a long way to go yet, and remember that we're already at 55° N latitude, the same as Newcastle-upon-Tyne and north of 95% of Canada's population.

From Novosibirsk, the Ob' launches itself across the vast, swampy West Siberian Plain, flowing northwest through the taiga for 2,000 km (1200 mi) to the point at the latitude of Anchorage where the Irtysh, itself one of Asia's longest rivers, flows into it. It then turns north-northwest, flowing for about 1200 km until it brushes against the Ural Mountains at Salehard on the Arctic Circle, then makes a right and flows east for 160 km (100 mi) or so into its estuary, the Gulf of Ob'. We're not done yet. The Gulf of Ob' is the largest estuary in the world; the river ends 800 km (550 mi) from the Kara Sea!

The Ob', by itself, is Siberia's third longest river. Combined with the Irtysh, it is the world's fifth longest river, 5410 km (3300 mi) long. The Ob'-Itrysh drainage basin covers 2,600,000 kmĀ² (1,125,200 sq mi), the largest in Asia and the fifth largest in the world.

Along most of its length, roads and railoads are not to be found; Ob' is the only highway.