ARKANSAS—ARIZONA 5d3 
Frost and Precipitation 
Frost Precipita- 
_ _ tion 
Station 7 Average Date of Date of _ 
vey ; Annual 
1st Inilling Last in Earliest | Latest Inches 
in Autumn Spring in Autumn | in Spring 
Favetteville Oct. 19 April 10 Sept. 29 April 30 44 3 
Dodd City Oct. 18 April 13 Sept. 29 May 1 47 2 
Pocahontas Oct 23 April 3 Oct. 8 May 2 43 5 
Fort Smith Nov. 4 Mar. 24 Oct. 15 April 6 41.8 
Conway Oct. 27 Mar. 28 Oct. 2 April 12 45 .4 
Little Rock Nov. 9 , Mar. 21 | Oct. 22 | April 14 49.6 
Helena Nov. 1 Mar. 25 Oct. 21 April 6 59.2 
Dallas Nov. 4 April 4 Oct. 7 | May 1 51.0 
Pine Bluff Nov. 6 Mar. 27 Oct. 19 April 19 48 § 
Camden Nov. 7 Mar. 24 Oct. 8 April 12 49 2 
Warren Nov. 4 Mar. 30 Oct. 10 April 8 49 0 
Arizona The drainage system is the Colorado 
Arizona has an area of 113,020 square 
miles. In the northern part, the state is 
a dry plateau, arid and of little value 
without irrigation. In the south it is 
mountainous, the valleys are broad, some- 
times 20 to 30 miles in width. The prin- 
cipal mountain masses are Castle Dome, 
Big Horn, Eagle Tail, Chocolate Dome 
Rock, Palomas Harquahala, San Fran- 
cisco and Black in the north central; Car- 
rizo, Lukakukia and Tunica in the north- 
east; Zuna, White Mogollon and Catalena 
in the southeast and south. San Fran- 
cisco mountain, above Flagstaff, is the 
highest, rising 12,794 feet above the sea. 
To the south the surface falls sharply to 
low ridges, mostly of volcanic origin, 
thence by terraced mesas down to the 
great desert plain little above sea level. 
This plain is cut by gullied stream beds 
in which the surface water from the occa- 
sional rainfall flows into the broad Gila 
valley. At Flagstaff the rainfall is 24.65 
inches; at Yuma, 2.84 inches. 
The sandy regions of the southwest are 
the hottest portions of the continent. It 
is common for the mercury to rise to 120 
degrees Fahrenheit in the shade during 
July and August, but the atmosphere is 
so clear that, while the sun is scorching 
in its heat, it is said not to be oppressive, 
and the winter climate is excellent. 
river with its tributaries, the principal of 
which is the Gila. 
There can be but little fruit grown in 
Arizona without irrigation. In the north- 
ern part of the state the Colorado river 
is the principal stream, but it runs in a 
deep canon, and at the present time there 
is no method provided that seems prac- 
tical for diverting or lifting the water 
from this deep bed for the purposes of 
irrigation. The rivers of Arizona draw 
moisture from the mountains, but these 
mountains are not covered with snow dur- 
ing July and August, the season when the 
moisture is most needed for irrigating 
purposes. The habit of flooding the land 
several times during the season when the 
snows are melting in the mountains, then 
cultivating intensively during the dry 
season, forming a dust mulch to conserve 
the moisture, has been successful for the 
growing of certain kinds of fruits and 
vegetables. This system is practiced 
largely in many sections of the state. 
The Temperature 
One of the principal difficulties in grow- 
ing fruit in Arizona is the extreme heat. 
The sun is so hot, and the air so dry, 
that the evaporation is very rapid, and 
even where there is plenty of water in 
the earth, the plant often fails to take it 
uy as fast as the sun evaporates it from 
