84 THE CLIFF RUINS OF CANYON DE CHELLY [ets any.16 
other high ground, the valleys being generally clear or covered with 
sagebrush. Still higher up yellow pines become abundant and in 
places spread out into magnificent forests, while in some mountain 
regions scrub oak, quaking asp, and even spruce trees are abundant. 
In the mountain regions there is often a reasonable amount of mois- 
ture, and some crops, potatoes for example, are grown there without 
irrigation; but the season is short. In the Tunicha mountains the 
Navaho raise corn at an altitude of nearly 8,000 feet, but they often 
lose the crop from drought or from frost. On the intermediate levels 
andin the lowlands cultivation by modern methods is practically impos- 
sible without irrigation, except in a few favored localities, where a crop 
can be obtained perhaps two years or three years in five. But with a 
minute knowledge of the climatic conditions, aud with methods adapted 
to meet these conditions, scanty crops can be and are raised by the 
Indians without irrigation throughout the whole region; but every- 
where that water can be applied the product of the soil is increased 
mnany fold. 
Near the center of the plateau country, in the northeastern corner of 
Arizona, a range of mountains crosses diagonally from northwest to 
southeast, extending into New Mexico. In the north an irregular clus- 
ter of considerable size, separated from the remainder of the range, is 
called the Carrizo; and the range proper has no less than three names 
applied to different parts of it. The northern end is known as the Luka- 
chukai, the central part as the Tunicha, and the southern part as the 
Chuska or Choiskai mountains, all Navaho names. The two former 
clusters attain an altitude of 9,500 feet; the Tunicha and the Chuska 
are about 9,000 feet high, the latter having a flat top of considerable 
area. 
On the east these mountains break down rather abruptly into the 
broad valley of the Chaco river, or the Chaco wash, as it is more com- 
monly designated; on the west they break down gradually, through 
a series of slopes and mesas, into the Chin Lee valley. Canyon de 
Chelly has been cut in the western slope by a series of small streams, 
which, rising near the crest of the mountain, combine near its head 
and flow in a general westerly direction. The mouth of the canyon is 
on the eastern border of the Chin Lee valley. It is 60 miles south of 
the Utah boundary and 25 miles west of that of New Mexico; hence it 
is 60 miles east and a little north from the old province of Tusayan, 
the modern Moki, and 85 miles northwest from the old province of 
Cibola, the modern Zuni. Its position is almost in the heart of the 
ancient pueblo region; the Chaco ruins lie about 80 iniles east, and the 
ruins of the San Juan from 60 to 80 miles north and northeast. 
The geographic position of Canyon de Chelly has had an important 
effect on its history, forming as it does an available resting place in any 
migratory movement either on the north and south line or east and 
west. The Tunicha mountains are a serious obstacle to north and 
