Dingbian County in northwestern Shaanxi, flowing through the Otog Banner and Uxin Banner in Inner Mongolia, and then flowing from the east of Batuwan Village into the territory of northern Shanxi, after converging with Xiangshui River. It flows into the Wuding River, a tributary of the Yellow River, to the southeast. In the loose Mu Us desert, a “U” shaped river valley is washed out. This river is known as the Sarawusu River. Sara Wusu in Mongolian means "thick yellow stream" after the eponymous perennially yellow-colored local river; on both sides of the river is covered with swaying red willows, so people also call this river "Hongliu River". In 1923, French Jesuit Émile Licent first discovered a fossil of the Hetao people here. Since then, Chinese archaeologists have visited the site many times. The site is known today as part of the Shuidonggou site complex. A large number of cultural relics have been excavated from this site, some reportedly dating back as far as 100,000 years; however, the chronology of the site remains debated. The material culture created by the Hetao people is now called "Salawusu" or "Shuidonggou" culture. After a comprehensive analysis of geology, animal fossils and stone tools, this culture was identified as the late Paleolithic culture. Hetao civilization is the product of the integration of grassland culture and Yellow River civilization. Its long-term development and complex transmutation process, especially the relationship with Urad and Ordos Mongolian culture, also illustrates the relationship between Hetao civilization and Yellow River civilization. Hetao culture is one of the important components of the mainstream culture of the northern grasslands. In the grassland culture, the Hetao culture is both a source and a stream. As a source, Hetao culture has a historical accumulation of symbiosis with the northern grassland culture. As a stream, it is different from the Mongolian classic culture in the eastern part of Inner Mongolia, such as Hongshan culture and Khorchin Mongols culture. It has its unique development trend. In the origin of grassland culture, it is a source of the late Paleolithic period, which originated from the prosperity of ancient ethnic minorities. It was formed in the Qin, Han, Ming and Qing dynasties, and it is a cultural system of modern and contemporary civilization. It is an independent unit culture circle of grassland culture and a complete regional cultural system, which plays an important role in the composition of