The Ulan Moron (mn|{{lower|0.2em|{{MongolUnicode|ᠤᠯᠠᠭᠠᠨMongolian: {{lower|0.2em|{{MongolUnicode|ᠮᠥᠷᠡᠨ,, lit. "Red River"; Chinese: 乌兰木伦, p ), Mar Qu (Tibetan), or Tuotuo River (Chinese: 沱沱河, p Tuótuó Hé, lit. "Tearful River";[1]) is a long river, located in Qinghai province in the People's Republic of China.
The Ulan Moron begins as melt-off from the Geladandong glaciers and runs to a confluence with the Dangqu or Dam Chu River, where they form the Tongtian River, which subsequently becomes the Yangtze River. Although the Dangqu has been found to be the source of the Yangtze under the usual modern criteria, the Ulan Moron has been traditionally regarded as the main river and source. It belongs to the East China Sea watershed basin.