SOUTHERN PACIFIC LINES 271 
On the south slope of these mountains, near Arrowhead Springs, 
there is a remarkable scar, like a huge arrow point. (See pl. 46, A.) 
It is not always conspicuous, its distinctness depending on light and 
foliage, but it can be easily discerned on close scrutiny. It is due to 
a peculiar-shaped area of bare rock ledges and thin vegetation, 1,375 
feet long and 449 feet wide, occupying an area of 7% acres. Near 
by is an interesting group of hot springs, some of which have tempera- 
tures exceeding 180° F.; here buildings have been erected to form a 
health resort. The water rises on the fault that defines the south 
margin of the range, and the heat is due to the great depth from which 
it comes. 
Three miles north of Colton is the prosperous city of San Bernar- 
dino (population 37,481), the county seat of San Bernardino County. 
This is the largest county in the United States, having an area of 
slightly more than 20,000 square miles, or almost equal to that of 
Massachusetts, Connecticut, and New Jersey combined. San Ber- 
nardino is built on the plain, about 5 miles south of the foot of the 
San Bernardino Mountains, and in the last 30 years or so it has grown 
into a large modern city with many industrial interests. About 
15,000 acres of land in the surrounding region is under cultivation, 
mostly irrigated by water from wells, many of them flowing, which 
draw their supply from the gravel and sand that constitute the plain. 
San Bernardino was the first Anglo-Saxon settlement in southern 
California, established in 1851 by a colony of Mormons sent from 
Utah by Brigham Young. They came through Cajon Pass (cah- 
hone’) and purchased from Mexicans the cultivated areas of the Ber- 
nardino ranch for $7,500. The region had long been occupied by 
settlers of Spanish origin. In 1810 a mission was established near 
Bunker Hill, but it was destroyed by the Indians. Later a larger one 
was begun at old San Bernardino, on the south side of the Santa Ana 
River. There the padres in charge dug ditches, beginning between 
1820 and 1830 with one from Mill Creek, which is the oldest ditch in 
the valley. In 1837 the mission lands were taken by the Mexican 
Government and given to Mexican settlers, and it was from one 
of these landholders that the Mormons purchased land for their 
settlement. 
At first the old ditches sufficed for the needs of the settlers, but as 
population increased other ditches were dug. In 1870 the Riverside 
colony, made up mainly of settlers from New England, began the 
first large canal, and in the next 20 years irrigation was extended over 
a wide area. The greater part of the running water and considerable 
underground water was utilized, mainly for irrigating oranges and 
other citrus fruits. Now a large area in the vicinity of San Bernar- 
dino, Redlands, and Riverside is under irrigation by water derived 
either from surface streams from the San Bernardino Mountams or 
from the underflow in the gravel at their foot. 
