This poem was written toward the end of 1935 when the Long March was almost finished. In it Mao listed some places Red Army had travelled through. Five Ridges and Wumeng are both big mountains in southwestern China. Jinsha is actually another name for certain parts of Yangtze River. Dadu River is at the west part of Sichuan, here in a heroic fight, 22 volunteers carried out a suicide attack on the KMT garrison across the iron-chained Luding Bridge and saved the Red Army from being destroyed. The Min Mountains are a mountain range at the Sichuan-Gansu border area, is already close to the end of Long March's route. To get rid of the pursuing KMT army, the Red Army had to climb over its 13000-foot peak and many froze to death on it.