Let me briefly talk about this matter. Gansu Province is called Gan for short. It is named after Guganzhou (Zhangye City) and Suzhou (Jiuquan City) in the province. Because Longshan in the province is a famous historical mountain, the province is called "Dragon Tour" in history, so it is also called "Dragon" for short. The reason why the image is as long and narrow as jade. There are three aspects of the relationship, one is geographical factors, considering the integrity of Qilian Mountain. From Dunhuang in the west to Tianshui in the east, it was handed down from Qilian Mountain, which is covered with snow all year round. A large area of land in western Gansu is irrigated by snow water. At that time, after liberation, the central government wanted to allocate the mountainous areas in northern Sichuan, including Jiuzhaigou, to Gansu Province, but the provincial government gave up as soon as there was no arable land. In that case, Gansu is the first tourist province in China, because Gansu is the throat of the vast western mountains and rivers of the motherland. The second factor is the historical factor. The famous Silk Road winds at the foot of Qilian Mountain. The continuation of history has created the same customs and social conditions. In order to preserve and continue this relative custom, the areas under the jurisdiction of Anxi Duhufu and Beiting Duhufu (established in the Tang Dynasty) were merged into one province (established in the Yuan Dynasty and still used by later generations). The third aspect is human factors. The territory of Gansu is different in the past dynasties, generally from Dunhuang to Hanzhong in Shaanxi. Due to the policies and preferences of the rulers, it was different from that at that time in some areas. After liberation, such territory was fixed. If the government at that time had a long-term vision, Jiuzhaigou belonged to Gansu, not Sichuan, because Huixian crossed a mountain and Wenxian in the southwest of Gansu was the border of Jiuzhaigou.

I don't know if you are satisfied with this answer. I come from Gansu. Can you imagine what I said above? I inferred it myself. Because I have not been exposed to the real historical data of Gansu Province, I only analyze and infer according to what I have learned. Let me get this straight. Listen.