Tingri County or Dhringgri County (Tibetan: དིང་རི་རྫོང་, Wylie: ding ri rdzong; Chinese: 定日县; pinyin: Dìngrì Xiàn), is a county of Xigazê in the Tibet Autonomous Region of China.The county comprises the upper valley of the Bum-chu or Arun River, with the valleys of its tributaries plus the valleys of the Rongshar Tsangpo and the Lapchi Gang Tsanpo which flow south into Nepal. It is bordered on the south by the main range of the Himalayas including Mt. Everest (Tib.