Short answers, pulled from the story.
The East Siberian Mountains are one of the largest mountain systems in the Russian Federation, located in Northeast Siberia. They span the region between the Central Yakutian Lowland and the Bering Strait, and the territory is counted among the Great Russian Regions.
The East Siberian Mountains region holds the record for the world's lowest temperatures for inhabited places. The Oymyakon Depression, in the southern part of the system, registers extreme low temperatures despite sitting roughly 3,000 km south of the geographic North Pole.
A kigilyakh is a rock formation found in parts of the East Siberian Mountains, specifically at the Kisilyakh Range and the Oymyakon Plateau. These formations are highly valued in the culture of the Yakuts.
The Siberian Salamander inhabits the rivulets and humid lower-altitude areas of the East Siberian mountain ranges. It is known for surviving deep freezes, enduring temperatures as low as -45 degrees Celsius.
The principal rivers of the East Siberian mountain region are the Yana, the Indigirka, the Kolyma, the Omolon (a tributary of the Kolyma), and the Anadyr.
The main group of ranges in the East Siberian Mountains stretches for nearly 3,000 km, from the Lena River valley to Cape Dezhnyov at the eastern end of the Chukotka Peninsula. The highland reaches a width of roughly 1,200 km and includes ranges rising both north and south of the Arctic Circle.