The history of Jiulong Mountain, legend has it that the yellow wind of the northern grassland is strange and the black water demon has been working for a long time, and the cave and wild river often flood. Shenmu County often suffers from mountain torrents. Every time the flood is flooded, the flood peaks outside the city wall are undulating and choppy, and there is a tendency to fall off the city head. The houses collapsed, the fields were flooded, people cried out to the sky, and they prayed to the sky.