… Gamble on the Pure One: the Yarlung Tsangpo River through history … Ruth Gamble on the Pure One: the Yarlung Tsangpo … borders of China and India. Ruth Gamble, a cultural and environmental historian of Tibet, spoke about the river as … entitled “Fear of the Pure One: What the Yarlung Tsangpo (Brahmaputra) River’s History Can Tell Us About Asia’s Water …