CHARACTERISTICS OF THE PLATEAU AREA. 
295 
which extends westward to the Sierra Abajo, and south to the Rio 
San Juan, a broad expanse fully justifying the name, which was given 
to it by Professor Newberry. Here and thereon this plateau are patches 
of pinon pine and cedar, the only tree- vegetation to be found in these arid 
regions. Beyond the Abajo Mountains the country presents the aspect 
of a plateau, arid aud waterless, and almost without vegetation. 
On the other side of this great plateau basin, the plateaus sloping 
eastward from the Wahsatch present features, in general, almost iden- 
tical with those on the eastern side — the same succession of steps from 
the higher to the lower plateaus, the same gradation in the vegetation. 
There are, rising out of these plateaus, a few groups of volcanic mount- 
ains, such as the Sierras la Sal and Abajo, the Henry Mountains, and 
El Lat6, which are partly clothed with timber, and around whose bases 
are belts of fine luxuriaut grass, resembling oases in a desert. 
The San Juan Eiver rises in the San Juan Mountains, in a number of 
branches, which, flowing southward from the mountains, unite in the 
plain at their base, and th ence pursue a general westward course to the 
Colorado. Among the lower spurs of these mountains, the streams 
have narrow grassy valleys, interspersed with timber. Away from the 
mountains, however, the omnipresent sage asserts proprietorship again. 
The river has a narrow flood plain, with groves of willows and cotton- 
wood, but here, as everywhere in this region, grass is scarce. South of 
the river, however, near the boundary between New Mexico and Arizona, 
is an extensive group of mountains, known as the Carrisos and Tuni- 
chas, the latter name being applied to the southern portion of the range. 
These mountains contain some timber near their summits, and are 
everywhere well grassed, while the valley of the Chelly west of the range, 
which forms the principal part of the Navajo Eeservation, is covered 
with exceptionally fine grass. Beyond this region, to the westward, the 
country north and south of the river goes from bad to worse, a country 
fit only for the habitation of the rattlesnake, tarantula, and coyote. 
The Colorado Chiquito heads in the western part of New Mexico, and, 
flowing at first westerly and then northwesterly over the Colorado Plateau, 
empties into the Colorado River. The plateau over which it flows has 
an elevation of 5,000 to 0,000 feet, terminating in a well-defined edge 
on the south and southwest, where it is much higher than the country 
beyond. In Western New Mexico and Eastern Arizona the southern 
border is crowned by the Datili Range. Northward the plateau stretches, 
a desert-like expanse, into the country above described. The greater 
part of this plateau, aud especially the northern portion, is barren and 
uninviting. About the course of the river it is less arid, while the im- 
mediate valley is described as grassy and fertile, but with very little 
timber. 
West of the river is the volcanic group known as the San Francisco 
Mountains, rising to a height of 12,500 feet. These mountains are 
densely timbered, as is also the plateau about their bases, while the tim- 
