pass in the outer eastern Carpathians of western Ukraine, an important route connecting the country's isolated western reaches with the rest of the republic and with northeastern Romania. The southern portion of the pass is formed by the valley of the Tisza River (also spelled Tisa, or Tysa), and the northern section contains the headwaters of the Prut. The head of the pass is 3,054 feet (931 m) above sea level and is crossed by a road and a railway line. The nearby mountains rise to more than 6,600 feet (2,000 m).