SIBERIA, INCLUDING the Russian Far East, covers 4.9 million square mi (12.8 million square km), an area that is three-fourths of the Russian Federation or onethird larger than the United States and one-fourth larger than Canada. Siberia stretches from the URALS in the west over 3,000 mi (5,000 km) to the Pacific Ocean in the east. It has borders with Kazakhstan, Mongolia, and China. In the very unlikely case that Siberia would separate from the Russian Federation, it would become a large state by its territorial size, but with a sparse population. Siberia’s size is not advantageous as the climate is usually very harsh with a marked continental climate. The northeastern part shows the coldest temperatures in the Northern Hemisphere with - 90 degrees F (-68 degrees C) at Oymyakon and Verkhoyansk in Yakutia. In summer, temperatures can reach 90 degrees F (32 degrees C). These great differences in temperature present a challenge for human colonization and exploitation of the rich natural resources (wood, coal, oil, gas, gold). Permafrost has a decisive impact on soil formation with the consequence that infrastructure is expensive to build. Therefore, the famous Trans-Siberian Railroad, built between 1891 and 1903, touches the southern belt of Siberia. Although Siberia is inhabited by nearly 45 different ethnic groups, Russians represent the majority. According to the census of 1989, 85 percent of the population are Russians. Russian colonization since the late 16th century resulted in a decline of the indigenous nationalities that counted more than 200 tribes before the Russian arrival. There are three great ethnic groups: Finno-Ugrians, Turco-Tatars, and Tungus and Paleo-Asiatics.