Crystal ice floats in the upper stream of Heihe River in Qilian County, Haibei Tibetan autonomous prefecture, northwest China's Qinghai Province. (China News Service/Zhang Hongke)

Known as the "mother river of the Hexi Corridor", Heihe River is the second largest inland river in China with a total length of 928 kilometers, extending the provinces of Qinghai, Gansu, and Inner Mongolia Autonomous Region. As temperature drops, drifting ice looking like a belt zigzags through Qilian Mountains.

Crystal ice floats in the upper stream of Heihe River in Qilian County, Haibei Tibetan autonomous prefecture, northwest China's Qinghai Province. (China News Service/Zhang Hongke)

Crystal ice floats in the upper stream of Heihe River in Qilian County, Haibei Tibetan autonomous prefecture, northwest China's Qinghai Province. (China News Service/Zhang Hongke)

Crystal ice floats in the upper stream of Heihe River in Qilian County, Haibei Tibetan autonomous prefecture, northwest China's Qinghai Province. (China News Service/Zhang Hongke)

Crystal ice floats in the upper stream of Heihe River in Qilian County, Haibei Tibetan autonomous prefecture, northwest China's Qinghai Province. (China News Service/Zhang Hongke)

Crystal ice floats in the upper stream of Heihe River in Qilian County, Haibei Tibetan autonomous prefecture, northwest China's Qinghai Province. (China News Service/Zhang Hongke)