Trans-Siberian Railway men and ammunition coming from west to east would have to wait in the sidings, whilst troops and injured personnel in a troop train travelling from east to west went along the line. Thus the Japanese were quickly able to advance whilst the Russians were awaiting necessary troops and supplies. After the Russian Revolution of 1917, the railway served as the vital line of communication for the Czechoslovak Legion and the allied armies that landed troops at Vladivostok during the Siberian Intervention of the Russian Civil War. These forces supported the White Russian government of Admiral Alexander Kolchak, based in
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