79 
for the climate is too arid for dry farming. Some of the water is ob- 
tained from San Felipe Spring, in the eastern part of the city, which 
has a flow of 50,000 gallons a minute (Meinzer). It issues from the 
top of the Georgetown limestone, probably rising through crevices 
from sandy beds at the base of the limestone or from sandstone of the 
underlying Trinity group. The original settlement here, owing its loca- 
tion to the great spring, was called San Felipe. Here an old Mexican 
trail joined the trail connecting El Paso with San Antonio and New 
Orleans. Turning eastward it crossed Mud Creek, 16 miles east of 
Del Rio, and went on through Fort Clark, Uvalde, Castroville, and 
San Antonio. To the west it reached the valley of the Devils River 
at Fort Hudson, considerably above its mouth, thus avoiding the 
deep canyons of the Devils River and Pecos River northwest of Del 
Rio. (See p. 80.) 
Not far west of Del Rio the Coastal Plain gives place to the ra 
province as the hard limestones of the Comanche series rise to 
surface. For the first few miles the railroad crosses 
SOUTHERN PACIFIC LINES 
Devils River. the alluvial river flat, reaching the bank of the Rio 
Elevation 955 feet. Grande at McKees siding. Here the valley develops 
oe vat OES into a shallow canyon which deepens toward the west 
as the massive Georgetown limestone gradually rises 
and presents cliffs along the river bank. The railroad follows the 
river to a point about 15 miles above Del Rio, where Castle Canyon, 
the mouth of the Devils River Canyon, affords a natural gateway to 
the mouth of California Creek, which breaks the west wall of the 
Devils River Canyon near milepost 395. The canyon scenery in this 
vicinity is striking, the high walls of massive Georgetown limestone * 
presenting a variety of picturesque erosional forms, some of which are 
shown in Plate 11, C. The fluted columns and recesses in the lime- 
stone are especially impressive, and there are many caves which 
afforded shelter and hiding places for the Indians who formerly in- 
habited the region and left hieroglyphs on the cliffs and cavern walls. 
These caves are now the resort of bats; in some of the smaller ones 
bees store large supplies of honey. Washita fossils have been collected 
nearly to the bottom of the canyon of Devils River, where the top of 
the Edwards limestone is e A conspicuous feature at Devils 
River station is the power plant that generates power for Del Rio and 
59 According to Dumblethereis at the 
base of the Devils River section a sandy 
water-bearing limestone which is tapped 
by wells on surrounding plateaus. The 
Roemer (at base), Pervinquieria leon- 
ensis Conrad (70 feet higher), Kingeana 
wacoensis Roemer, and at the top a bed 
with many large Caprinula? crassifibra 
Roemer, overlain by marly beds with 
other Washita fossils and a more mas- 
sive bed which extends to the base of 
the Del Rio clay farther east. 
