Gansu (kan su) Province is located in the People’s Republic of China’s northwest. It borders Mongolia to the northwest, and the Huang He River flows through the southern part of Gansu. Its capital is Lanzhou. Home to 26 million people today, Gansu is populated by mostly Han Chinese, yet still includes some Tibetan, Mongolian, and other minorities. Most of Gansu’s Tibetans live in Gannan Tibetan Autonomous Prefecture, which is located in the southwestern section of Gansu, where they make up over 50% of the population.
Gansu was part of the Mongol Empire from the 13th to 15th centuries, and its one appearance in the Blue Annals comes in this context. In Chapter 4 Sakya Panchen (sa skya pang chen) or Kunga Gyeltshen (kun dga' rgyal mtshan), son of Palchen Öpo (dpal chen 'od po), visits the “emperor” (actually a Mongolian fief) Godan in Gansu in 1244 {R 211}. Godan was the grandson of Genghis Khan, and was fief of some of the Tibetan-inhabited areas once belonging to the Western Xia Dynasty in Gansu and Qinghai. Godan also kept tabs on the activities of Tibetan monasteries.
Gansu is also mentioned in a footnote of the Roerich translation, which notes that the remains of Ma ting pa (pham¬ mthing pa) or Vāgīśvarakīrti, who was a Guhyasamāja scholar, are preserved in Gansu where he died on pilgrimage, returning from Wu tai shan {R 227}.
China Tibet Information Center
Blue Annals, Chapter 4