Mongolia has traditionally been a land of pastoral nomadism; livestock raising and the processing of animal products are the main industries. Wool, hides, meat, cloth, and leather goods are exported. Irrigation has made some agriculture possible; wheat and oats are the chief crops. Coal, iron ore, gold, and oil are important mineral resources. Mongolia is crossed north to south by a railroad linking Beijing with Russia. The region has an adequate system of roadways, although most roads are unpaved. Camels and yaks are often used in desert and mountain areas. Trade traditionally has been greater with Russia than with China, but this has been changing in recent years.