304 The American Geologist. November, 1903. 
2. — This zone includes all the lands whose altitude is be- 
tween 4900 and 5800 feet. In it common juniper, Juniper 
occidentalis (cedar), piiion, and cactus flourish, and grass 
grows fairly well. 
3. — All lower Canyon creek, Cherry creek and Salt river 
camons, the foot hills of the Apache mountains, and the re- 
gion of the Hinton formation included between the altitudes 
of 3500 and 4900 feet are known as the zone of Cactus, 
Agam, Obione and Artemisia (Grease-wood and Sage-brush). 
It is further characterized by the fact that its grass (Filaree 
ai'.tl Grama) with few exceptions is poor, the soil on which 
it grews being derived from granitic or late volcanic rocks. 
4. — This is a zone of Cactus (Cereus giganticus predom- 
mat'ng), Yucca, and Agave (mescal, most related to Agave 
e'ecipiens). The altitude of this zone is from 3000 to 3500 
fe-^t. It has a scanty vegetation, scarcely any grass at all; 
but where there is water, a most luxuriant vegetation springs 
up. 
Irrigation. 
Though the region described in this paper exceeds 6000 
square miles, only 5000 acres ( at most) are under cultiva- 
tion, not because of a lack of water, but because the streams 
are all inclosed within narrow and deep canyon walls. There 
an a few places, however, where ditches could be taken out 
an-i more land irrigated, but in these places (Forest Dale, 
and in the Middle Carrixo and Cibicu valleys) the streams 
from which the water must be taken are dry creeks most of 
the year. What is really needed is a series of storage reservoirs 
thai will catch the water in flood time and hold it till a time 
of need. As the lands are mostly on Indian reserves, steps 
are already being taken by the government to build such 
d^ms that the Indians may have more lands to farm and 
become self-supporting. That storage reservoirs will prove 
a success is shown by the fact that a prehistoric people built 
a village two miles west of the Grasshopper springs so that 
it dammed the outlet to a stream and from the water thus 
stored they irrigated lands enough below the village (several 
hundred acres as is indicated by the ditches) to supply food 
for at least 500 people, not for a short length of time but 
for a great many years, as their graveyard attests. 
