Helan Mountains
From August 1950, the PLA 6th Cavalry Division, 7th Infantry Division, and troops from the Pingliang and Qingyang Military Sub-Districts totaling more than 15,000 begun their operation against the more than a dozen bands of bandits headed by chieftains including Guo Shuanzi (郭栓子), Ma Yanbiao (马彦彪), Ma Guoyuan (马国援) and others in Xiji (西吉), Longde (隆德), Helan Mountains and Hexi Corridor regions. After one year and eight months, the 2,000 bandits in the regions were killed.