10 
THE GEAND OA5TON DISTEIOT. 
country. North of it rise the High Plateaus of Utah; to the eastward are 
the central regions of the Plateau Province; and to the southward and west- 
ward is a sierra country, which remains to be well explored before its dis- 
tinctive features can be described. Upon the west the district terminates 
abruptly upon the brink of a great wall, where the surface of the country 
drops at once from an elevation of more than 6,000 feet to levels ranging 
from 1,300 to 3,000 feet above the sea. Every traveler in the far west has 
noted the desolate character of the country through which the Central 
Pacific Railway in Nevada is laid; and every feature of that desolation is 
intensified in degree, though identical in kind, in the nameless and formi- 
dable desert which lies west of the Grand Canon district. 
It is not altogether clear where the boundaries of the district should be 
drawn, nor what it should be made to include. So far as the western 
boundary is concerned there is no room for debate. It lies along the great 
escarpment which ovei’looks the rugged sierras and desert. From the very 
foot of that wall the calm repose of the strata with horizontal surfaces 
changes at once to the turmoil of flexed beds and jagged mountain crests. 
It is a portion of that trenchant boundary line which separates the topogra- 
phy of the Plateaus from that of the Great Basin and of the region south 
of the Great Basin so sharply that we may almost hurl a stone from one 
region to the other. But it is not so obvious where the eastern limit should 
be di’awn. The Grand Canon receives from the north the drainage of four 
distinct plateaus: the Sheavwits, Uinkaret, Kanab, and Kaibab. East of 
these lies a fifth, the Paria Plateau, which drains into the Marble Canon, 
and the Marble Canon is but the prelude to the Grand Canon. Structurally 
the Paria Plateau is quite similar to the others ; it has shared in their histoiy 
and evolution, and its topography is substantially the same in many respects, 
though not in all. It differs from the rest mainly in l}dng at a lower level 
and in the fact that the greater portion of its surface is covered with Trias- 
sic rocks, while the others present an almost unbroken expanse of Carbonif- 
erous beds. These two facts run otf into consequences which are very 
interesting in themselves, but which often mar the simplicity which is pre- 
sented to the mind in the study of the Grand Canon district, as limited to 
the other four plateaus. Hence it will be convenient to play fast and loose 
