Trans-Siberian Railway Similar to the First Transcontinental Railroad in the US, Russian engineers started construction at both ends and worked towards the centre. From Vladivostok the railway was laid north along the right bank of the Ussuri River to Khabarovsk at the Amur River, becoming the Ussuri Railway. In 1890, a bridge across the Ural River was built and the new railway entered Asia. The bridge across the Ob River was built in 1898 and the small city of Novonikolaevsk, founded in 1883, grew into the large Siberian city of Novosibirsk. In 1898 the first train reached Irkutsk and the shores of
West Siberian taiga Siberian taiga ecoregion, which is colder and more rugged in terrain. The southern edge of the region lies north of the belt of temperate forests and forest-steppe that runs along the Trans-Siberian railway. Because the West Siberian ecoregion is thus outside of the normal agricultural and developed strip of southern Russia, it is sparsely populated, although the city of Yekaterinburg is at the extreme southwest corner of the region. The city of Surgut is the largest city in the interior (with just over 300,000 inhabitants). To the north is the tundra of the Yamal-Gydan tundra ecoregion (covering the Ob River