The Siberian tiger, also known as the Amur, Altaic, Korean, North Chinese or Ussuri tiger, is a subspecies of tiger which once ranged throughout Western Asia, Central Asia and eastern Russia, and as far east as Alaska during prehistoric times, though it is now completely confined to the Amur-Ussuri region of Primorsky Krai and Khabarovsk Krai in far eastern Siberia, where it is now protected. It is the biggest of the eight recent tiger subspecies and the largest living felid, attaining 710 lbs in an exceptional specimen.