The building of the Trans-Siberian Railroad in the 1890s and Omsk's position as a transshipment point on the Irtysh led to rapid commercial growth. Industrial growth was given great impetus during World War II, since which time its population has more than trebled. Pipelines from the Volga–Urals and West Siberian oil fields supply the refinery and petrochemical industry, which makes synthetic rubber and tires. Engineering, especially the production of agricultural machinery, also dominates a wide range of industry. Other industries include the manufacture of cotton and woollen textiles, cord, footwear, and leather goods and food processing. Timber working is also carried on. Among the cultural and educational facilities of Omsk are agricultural, engineering, medical, and veterinary institutes and other research and higher educational establishments. Pop. (2006 est.) 1,138,822.

oblast (region), west central Russia, in the basin of the middle Irtysh River. Its entire surface is an extremely flat plain, with extensive marshes and peat bogs in the north and innumerable lakes, of which Lake Tenis is the largest. Many southern lakes are saline. In the north is a dense, swampy forest, or taiga, of pine, fir, spruce, and birch; this yields southward to forest-steppe, with groves of birch, and finally to true steppe. The forest-steppe and steppe have rich soils and are intensively cultivated. Much land was plowed up in the Virgin and Idle Lands Campaign of the 1950s. Agriculture dominates the economy, and the towns, apart from Omsk city, the oblast headquarters, are small food-processing centres. Grains, especially spring wheat, are the main crop; flax, sunflowers, and mustard are also important. Around Omsk city, market gardening is significant. Livestock husbandry and dairying are highly developed, with large numbers of cattle and sheep. Some timber is cut in the north. Area 53,900 square miles (139,700 square km). Pop. (2006 est.) 2,034,590.