According to the legend ancient, sage Asit Muni had his hermitage here. All his life, he bathed daily both in the Ganges and the Yamuna. Unable to go to Gangotri during his old age, a stream of the Ganges appeared opposite Yamunotri for him. The temple and the place opens every year on the auspicious day of the Akshaya Tritya, which generally falls during the last week of April, or the first week of May. The temple always closes on the sacred day of Diwali in mid-October - first week of November, with a brief ceremony. The temple staff return to their villages and for the rest of the time the valley is gripped in no-man silence and covered with a white sheet of snow. With the melting of the snow next summer, the temple re-opens to the blissful happiness of thousands of visitors again.

The daughter of the Sun god, Surya and consciousness, Sangya the birth place of the Yamuna is the Champasar Glacier (4,421 m) just below the Banderpoonch Mountain. The mountain adjacent to the river source is dedicated to her father, and is called Kalind Parvat, Kalind being another name of Surya.