196 EL PASO AND VALLEY OF THE RIO GRANDE. 
it with the range on the eastern side, is another ele- 
vated chain, much broken and very rugged. This is 
without timber and quite barren. 
Cactaceous plants abound on these mountain sides, 
and on the spurs leading from them. The yucca, 
Spanish bayonet, mezquit, larrea, and the various 
plants peculiar to desert regions, and the great pla- 
teau are found here. The lower spurs and intervening 
valleys are, in many places, covered with grama grass. 
The bottom lands are not grassy, as many suppose, but 
are entirely bare, save in isolated spots ; hence it 
is necessary to drive mules and cattle to these hills 
and valleys to feed. There are, however, some por- 
tions of the higher valley above Frontera where graz- 
ing is to be found. 
The height of the valley at El Paso was found 
to be 3,800 feet above the level of the sea. At 
Dona Ana, sixty miles above, on the river bottom, 
4,060 feet. At Albuquerque, about two hundred and 
fifty miles above El Paso, Dr. Wislizenus found the 
elevation to be about one thousand feet higher ; and 
supposing the circuitous course of the river through 
this distance to amount to four hundred miles, the fall 
of its water would be on an average two and a half 
feet per mile. But the sinuosities bear a greater pro- 
portion than this to the distance ; for, in a direct line 
of about thirty miles from El Paso to the initial point, 
surveyed by Mr. Radziminski, Principal Assistant Sur- 
veyor of the Commission, the river was found to 
measure a fraction less than ninety miles. 
