Both run nearly due north, and the former has a fall of about 2,000 feet
from the divide, near the southern reservation line, to the northern
boundary, a distance of about 85 miles. Chaco valley heads farther south
and discharges into San Juan river within the reservation. It has less
fall than the Chinlee. Both valleys are shown on the maps as occupied by
rivers, but the rivers materialize only after heavy rains; at all other
times there is only a dry, sandy channel. Chaco “river,” which heads
in the continental divide, carries more water than the Chelly, which
occupies Chinlee valley, and is more often found to contain a little
water. The valleys have a general altitude of 5,000 to 6,000 feet above
the sea.

The base of the mountain range has an average breadth of only 12
or 15 miles, and it is a pronounced impediment to east-and-west
communication. It is probably on this account that the Navaho are
divided into two principal bands, under different leaders. Those of one
band seldom travel in the territory of the other. The Navaho of the
west, formerly commanded by old Ganamucho (now deceased), have all the
advantages in regard to location, and on the whole are a finer body of
men than those of the east.

On the west the mountains break down into Chinlee valley by a gradual
slope--near the summit quite steep, then running out into table-lands
and long foothills. This region is perhaps the most desirable on the
reservation, and is thickly inhabited. On the east the mountains descend
by almost a single slope to the edge of the approximately flat Chaco
valley. In a few rods the traveler passes from the comparatively fertile
mountain region into the flat, extremely arid valley country, and in 50
or 60 miles’ travel after leaving the mountains he will not find wood
enough to make his camp fire, nor, unless he moves rapidly, water enough