To the southeast of the Manchurian Plain is a series of ranges comprising the Ch'ang-pai, Chang-kuang-ts'ai, and Wan-ta mountains, which in Chinese are collectively known as the Ch'ang-pai Shan, or Forever White Mountains; broken by occasional open valleys, they reach altitudes mostly between 1,500 and 3,000 feet. In some parts the scenery is characterized by rugged peaks and precipitous