The Qinghai-Tibet Railway extended its way into Gulu Town in Nagqu County in northern Tibet -- the last stop before it reaches Lhasa -- on Wednesday afternoon, said the railway headquarters.

Gulu Town is only 217 km away from Lhasa, and construction is proceeding as scheduled, according to sources from the railway construction headquarters.

With an average altitude of 4,500 meters above the sea level, Nagqu area is located amid the Tanggula, Gangdise and Nyainqentanglha ranges, all sacred mountains regarded as "insurmountable even by eagles" in the eyes of locals.

Currently, workers are laying tracks on the Nagqu area in freezing snows and biting winds, where the average temperature is normally 30 Celsius degree under zero, an official in charge of the area's railway construction told Xinhua.

The 1,142-km Qinghai-Tibet Railway from Golmud in Qinghai Province to Lhasa is the most elevated rail route in the world, reaching an altitude of up to 5,070 meters.

Since the railway entered Tibet at Amdo County, some 440 km from Lhasa in June, track-laying on approximately 240 km of the railway within in Tibet has completed.

China began building the Qinghai-Tibet railway in 2001. The raiway, the cost of which is expected to be 26.2 billion yuan (3.16 billion US dollars), is scheduled to open in 2007.

Tibet, with an area of more than 1.2 million sq km, approximately one eighth of China's territory, was the only provincial area in China without an inch of operating railway, and poor traffic conditions have been one of the major obstacles to its modernization.

About 90 percent of the 2.7 million Tibetans live on farms or breed livestock.