For more than 150 years, coal was the dominant fuel supporting Russia's industries, and many industrial centers were located near coal deposits. In the 1960s, oil and natural gas overtook coal when plentiful reserves of those fuels became available and the coal shafts of the European Soviet Union (located primarily in what is today Ukraine) were being exhausted. Russian coal reserves are estimated at 200 billion tons, an amount that experts say is more than ample for current usage trends. Siberia and the Far East produce about three-quarters of Russia's coal, with the European contributions coming largely from the Vorkuta field (Pechora Basin) in Komi, the Urals, the eastern Donets Basin in the southwest, and the Moscow Basin. Largely untapped coal fields lie in the Siberian Tunguska and Lena basins. Productive fields in Siberia are located along the Trans-Siberian Railroad, making their exploitation more economical. The largest operational sources in that region are the Kuznetsk, Kansk-Achinsk, and Cheremkhovo fields. Coal is one of the less important sources of energy because its labor-intensive extraction makes production much more costly than other fuels. Rossugol', the Russian coal company, controls coal production through regional associations that are organized as joint-stock companies. Russian coal production has declined markedly over the last decade, and the coal industry has suffered a long series of strikes. Coal miners, among the best paid industrial workers of the Soviet period, have organized strikes that have gained national attention to protest the industry's long delays in paying wages. Experts predict that coal output will continue to dwindle as its relative usefulness in industry and domestic applications is reduced. In 1994 Russia produced 249 million tons of coal, and in 1995 the total rose to 255 million tons. Production for the first quarter of 1996 was 71 million tons.