The track goes along the Tsang Po valley

Qinghai-Tibet Railway is the world's highest railway. Some 960 kilometers of its tracks are located 4,000 meters above sea level and the highest point is 5,072 meters.
The railway extends 1,972 kilometers from Qinghai's provincial capital Xining to Lhasa in Tibet. The Golmud-Lhasa section zigzags 1,142 kilometers across the Kunlun and Tanggula mountain ranges.
About 550 kilometers of the tracks run on frozen earth, the longest such railroad on earth.
Tanggula Railway Station (5,068 meters above sea level) is the highest railway station in the world.
Fenghuoshan Tunnel (4,905 meters above sea level) is the world's most elevated tunnel on frozen earth.
Kunlun Mountain Tunnel (1,686 meters) is the world's longest high altitude tunnel built on frozen earth.
There are a total of 45 stations along the rail line.
The maximum train speed is designed to reach 100 km per hour in the frozen earth areas and 120 km per hour on non-frozen earth.