Of the four tribes, Ula was the economic and cultural powerhouse of Manchuria. The Ula tribe were mostly traders, buying horses, livestock, and fur from the steppe Mongols and selling them at the Jianzhou plateau on the Liao river basin, the economic center and farmland of the Manchu region. They in turn buy grains such as millet and corn at Jianzhou and sell them to the Mongols. The Ula Naras, for a large part, controlled trade between Manchuria and Mongolia by controlling the mountain pass at modern day Baicheng, Jilin, where the only passage between the two areas was located.