Dangqu

The Dangqu, Dam Qu or Dam Chu is the longest source of the Yangtze River, with a total length of located in the Qinghai province of the People's Republic of China. It runs from its source in an eastern offshoot of the Tanggula Mountains, receives its main tributary the Buqu-Gar Qu River, and has a confluence with the Ulan Moron, where the Tongtian River is formed. The Dangqu has been discovered to be the actual and the longest headwater of the Yangtze River under modern criteria, although the nearby Ulan Moron or Tuotuo was traditionally regarded as the primary river of the two.

Moron Us

Traditionally, the Dangqusometimes under the name Akdam, Akedamuqu, or A-ko-ta-mu-ch'üand the Buqu were both regarded as tributaries of the Garqu, then known as the Moron Us or Dequ. Under modern criteria, the Garqu is instead considered to be a tributary of the Buqu.