Chigan, which occupies a tropical latitude, is a region of steep mountains and deep valleys connected by narrow, precarious, or seasonally closed passes. The region is about 800 miles east to west and 300 north to south at its widest point. It is surrounded by high-altitude steppes to the north, desert to the east and west, and tropical lowlands to the south. The region internally can be divided into an endless series of highland peaks and lowland valleys. During the hot lowland summers, rivers flow swiftly with runoff from the mountains above. Winter temperatures are mild (in the lowlands, at least), but frequent storms drop heavy snow on the mountains and rain on the lowlands. However, the mountaintops are high enough to be permanently covered in snow, with the only difference between seasons being the extent of the snowpack and the ferocity of winter snowstorms. The lowlands are rich with vegetation and fertile soil. Where land has not been cleared for settlements and agr