oblast (province), extreme eastern Kazakhstan, in the Altai Mountains on the frontier with China, with an area of 37,550 sq mi (97,300 sq km). Its capital is Ust-Kamenogorsk.

It is drained by the upper Irtysh River, and Lake Zaysan lies in the south. The climate is continental and dry. One of the main centres of nonferrous metallurgy in Kazakhstan, the oblast has rich deposits of zinc, lead, and copper, as well as gold, silver, and other metals, which have been exploited since the late 18th century. The principal mines are at Leninogorsk, Zyryanovsk, and Belousovka. A major copper-mining centre was under development at Nikolayevka in the late 1970s. Cheap power is provided by the Ust-Kamenogorsk and Bukhtarma hydroelectric stations on the Irtysh.

Engineering products include drilling and flotation machinery, automated instruments, and capacitors. Agriculture mainly involves stock raising, but wheat and sunflowers are also grown. Other activities are fishing, forestry, fur trapping, and beekeeping. About 70 percent of the population is Russian and 23 percent Kazakh. Pop. (1991 est.) 949,000.