(also Richthofen Mountains), a mountain range in China. A northern spur of the Nan Shan system, the Ch’ilien Shan is more than 500 km long, with elevations of up to 5,934 m. The range is asymmetric. The northern slope is up to 40 km long, and its relative elevation above Hohsi Corridor reaches 4,500 m; the southern slope extends for 12 to 15 km, and its relative elevation reaches 2,500 m. The crest is massive, with an average elevation of about 5,000 m; there are passes at elevations of 3,500 to 4,500 m. The valleys of the Sule Ho and Hei Ho transect the range, which is composed mostly of shales, sandstones, and limestones. In the western part of the range there are deserts, dry steppes, and, above 4,000 m, mountain deserts. In the more humid eastern part, which is subject to the long-range effect of the summer monsoon, there are mountain meadows on loesses; the northern slopes have tracts of coniferous forest. The range was explored in 1894 by V. A. Obruchev, who named it in honor of F. von Richthofen.