Geological Survey Bulletin 845 Guidebook of the Western United States: Part F. Southern Pacific Lines

SHEET No. 17 (click in image for an enlargement in a new window)

Etholen is near the divide between the elevated basin that lies east of Sierra Blanca and the deep valley which has been excavated by the Rio Grande. To the northwest of this divide the railroad descends a steep grade past Lasca and Torcer sidings. In this vicinity the railroad crosses the old "salt trail" from the Indian villages on the Rio Grande to the great salt flats 45 miles northeast of Sierra Blanca, which were an important source of supply for many years and the cause of bitter controversy and hostilities.

At Torcer the road begins a very tortuous course to distribute the grade, and there are many curves, one of which is shaped like a huge horseshoe. These are along the east slope of the Malone Mountains, and in places the railroad touches the hard rocks of that range, but most of the descent is in valley fill, which is 600 feet or more thick. The descent to Small siding is about 550 feet in a distance of 12 miles. In this descent there are good views of the Malone Mountains, to the southwest, and the Finlay Mountains, to the northwest. The Finlay Mountains consist of a dome-shaped uplift of the strata, truncated at the top, so that a considerable area of underlying limestone and shale of Permian age is exposed. The surrounding ridges consist of sandstones and limestones of the Trinity group (Comanche series), of which about 800 feet is exposed. These strata are intruded by igneous rocks at several places.

From Small siding the railroad proceeds west down a small valley cut deeply in pink loams or sandy clays; these appear to have been deposited in a lake that once occupied the area, probably caused by the damming of the Rio Grande temporarily by some earth movement. About 1-1/2 miles beyond Small and at intervals to Finlay there are fine views of the Malone Mountains⁸⁴ showing sharply flexed limestones of Jurassic age. The most noticeable feature is a syncline or trough, which is clearly discernible from the train, as shown in Plate 17, B.

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⁸⁴According to Baker, the dominant structure in these mountains is a syncline overturned on its southwestern flank, a feature which is conspicuous from afar along the summit of the main ridge. The valley southwest of this ridge follows the axis of an anticline overturned to the northeast and so truncated by erosion as to expose the gypsum (Permian) that lies not far below the base of the Malone formation. The northwestern part of the mountain mass on the southwest side of this overturned syncline is anticlinal in structure, with the axis pitching southeastward. The main anticlinal axis passes near the gypsum quarry on the railroad. On the southeast side of the syncline there is an overthrust to the northeast. There is much minor crumpling on the southeast end of the main northeastern ridge. The general features are shown in Figure 24.

FIGURE 24.—Section across the Malone Mountains, Tex. After C. L. Baker (personal communication). Jm, Malone limestone (Jurassic). Cp, Limestone, etc.; g, gypsum (both Permian)

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PLATE 17 A (top), BADLANDS LAKE BEDS IN VALLEY OF RIO GRANDE WEST OF FINLAY, TEX. (P. B. King). B (bottom), OVERTURNED SYNCLINE OF MALONE MOUNTAINS, TEX. Looking southeast. (P. B. King)

Flexing and faulting have brought Permian gypsum to the surface along the railroad halfway between mileposts 756 and 757, where it is extensively quarried for use as plaster of Paris.⁸⁵ The quarry is south of the tracks. Near the quarry the gypsum is overlain by 200 feet of conglomerate and light-brown conglomeratic sandstone, which is overlain by limestone interbedded with sandstone, the latter in part conglomeratic. Certain fossils at this horizon are believed by Baker to indicate Cretaceous age but earlier than any Trinity elsewhere in Texas. The gypsum is known to be of Permian age because an overlying limestone, exposed half a mile east of Torcer siding, carries the characteristic fossil Richthofenia. Next above this are Jurassic beds.

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⁸⁵Gypsum consists of calcium sulphate with about 20 per cent of combined water. Plaster of paris, which is used extensively in the arts, is made from it by "cooking" the gypsum at a moderately high temperature to drive off part of the combined water and grinding the resulting mass to fine powder.

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The gypsum also underlies the flat between the southeast end of the Malone Mountains and the intrusive mass of the Quitman Mountains. In the foothills of the Malone Mountains it is overlain by conglomerate (basal Malone) of limestone and chert, including boulders as much as 8 inches in diameter, one of which yielded remains of Fusulina elongata, a fossil of Permian age. These boulders were of derived from the underlying strata. This basal conglomerate is by limestone containing conglomerate and brown sandstone layers, all of Jurassic age (Malone formation). On the east side of this area the gypsum is apparently overlain by brown sandstone and blue limestone of the Malone formation, dipping southwest.⁸⁶

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⁸⁶The Jurassic rocks of the Malone Mountains (Malone formation) consist of blue and gray limestones with a few intercalated layers of conglomerate and sandstone, having a thickness of about 1,000 feet. At the base is a conglomerate member, in places 50 feet thick, containing many limestone boulders. Some of the strata contain molluscan fossils of Jurassic age. The fossils are most abundant, so far as reported, in low, detached hills about 2 miles east of Torcer siding at a horizon believed to be about 300 feet above the base of the formation. The intricate folding and complex faulting in these mountains renders it difficult to determine the thickness and succession of the rocks. Owing to overturning of the folds some of the older beds lie on younger ones; this is likewise the ease with the Cretaceous strata in the Quitman Mountains, to the southeast. Some of the most distinctive fossils found in the Malone formation are ammonites and gastropods in considerable variety, but there are also many other forms. (Described by Cragin.)

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West of the gypsum quarry the railroad ascends a low ridge from which there are fine views of the Finlay Mountains, to the north, and of the Sierra del Presidio, far to the south in Mexico; the latter is more closely approached after the descent is made into the valley of the Rio Grande.

Finlay is a small settlement on the high alluvial plain northwest of the Malone Mountains. Near by are several small knobs of limestone, some of them Jurassic, and some Cretaceous (Finlay), with members of conglomeratic sandstone. About 12 miles due south, near the Rio Grande, are the ruins of Fort Quitman, once an important army post when the Indians were on the warpath.

West of Finlay there is another long tortuous descent of nearly 400 feet into the valley of the Rio Grande. There are many cuts in lake beds, in most places eroded into badland forms, notably at points 2 miles beyond Finlay, at Stevenson siding, and thence to Madden and beyond. The material is a pink sandy clay of compact texture, with a few harder sandy beds. Badlands such as are shown in Plate 1 from rapid gullying in soft beds that are sufficiently compact to sustain steep slopes. In the next 5 miles the valley of the Rio Grande is reached, and the railroad curves to a northwest course, which continues for 60 miles to El Paso.

The uplifts that followed the time of great volcanic activity in western Texas strongly effected the preexisting drainage, forming basins between the mountain blocks, some of which still exist. A wide trough excavated by the Rio Grande was dammed by the uplifts in the Big Bend region, causing a lake or series of lakes extending up the valley to the mountains at El Paso. In these waters were deposited a thick mass of fine-grained sediments, in large part of flesh color, orange-brown, and pale grayish green. Some beds are sandy, and thin sandstone layers are included; where these deposits are near the mountain slopes much coarse material is present. The lake beds were capped by stream deposits, which now fill many old gaps and extend over moderately high divides. North of Fort Bliss holes 2,300 feet deep have failed to reach the base of the valley fill.

The lacustrine condition in the Rio Grande Basin was terminated by the deepening of the outlet; this finally tapped off the water, and then, as canyons were cut through the ridges, a deep valley was developed. As the process continued, the side streams and arroyos cut deeply into the alluvial capping and the underlying lake deposits, and in the main valley terraces and a wide alluvial flat were developed.

McNary, formerly known as Nub, has developed into a small town for local trade in the irrigated district along the Rio Grande. This valley, with rich bottom-land soils, mild climate, wide areas of level surface, and a large water supply from the river now controlled by the Elephant Butte Reservoir, has developed rapidly in recent years. Much of the land from McNary to El Paso is under irrigation and is yielding large crops of cotton, alfalfa⁸⁷ and other forage plants, grain, fruits, and vegetables. The railroad passes near or through cultivated fields for the entire route, in striking contrast to the sand hills and barren lands of the area above the ditches. The alfalfa fields are usually of a rich green color, which becomes shaded with the lavender of the sweet-smelling blossoms when the plant is left to continue its growth for the development of seed. In 1929 the irrigated area in Hudspeth County was about 14,000 acres and in El Paso County 65,442 acres, an increase in the two counties of two and one-fourth times in 10 years. From McNary northwestward the railroad skirts the foot of the steep slope demarking the higher terrace. To the southwest are wide areas of irrigated lands, and across the river to the south are fine views of the high and picturesque front of the Sierra del Presidio, in Mexico. It consists of strata of Comanche age. A mile west of McNary is the 5,000-acre cotton plantation named "Algodones" (ahl-go-do'nace, from Spanish algodon, cotton), on which most of the water is pumped from shallow wells by electric power.

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⁸⁷Alfalfa (lucern in Europe) has long been cultivated as forage, for historians record its introduction into Greece from Persia as early as the fifth century before Christ. Its cultivation was attempted by early colonists in America, but not until 1854, when a variety from Chile was introduced into California, did its development proceed rapidly. Alfalfa is best adapted to semiarid regions, for it does not require a moist climate and does not suffer from extreme heat or from relatively severe cold. It thrives best under irrigation, an occasional flooding being necessary for its growth. It has been found by the Arizona Agricultural Experiment Station that 600 gallons of water is required to raise 1 pound of alfalfa. Besides being highly nutritive and palatable, alfalfa, when well rooted, is of rank growth, long lived, and hardy. Some fields are 25 years old, but on most soils the best yields are obtained in the third to seventh years. The roots range from 6 to 15 feet in length. Though alfalfa fields can be started in some places with a pound of seed (about 220,000 seeds) to the acre, about 15 pounds is used on irrigated lands. In places alfalfa is cut three to five times a year and therefore produces a larger yield than any other forage plant in the western United States. In some localities the plant is allowed to ripen in order to develop the seed, which is in considerable demand.

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Among the many frontier military posts established by the Government the garrison at Fort Hancock was regarded as one of the most important, for it guarded the San Antonio mail road through the Rio Grande Valley below El Paso as far as Fort Quitman, 20 miles away. The ruins of some of the old buildings are still visible a short distance from the tracks about half a mile west of the station.

In this part of the valley the railroad passes along the edge of the sand hills at the foot of the terrace that rims the valley. This terrace, which consists of sand and gravel, slopes upward to the foot of the high plateau extending northwest from the Finlay Mountains. This plateau is capped by the Finlay limestone, dipping to the southeast at a very low angle. At one point 8 miles northwest of Fort Hancock a butte of shale of Trinity age protrudes through the terrace deposits. The wide terraces adjoining the Rio Grande in this region consist largely of lake deposits laid down when the river was blocked for a period (p. 120) and detritus washed from the ridges to the north. Some of the material is loose sand, and in many areas this has been blown by the wind into sand dunes.

Northwestward from Fort Hancock the railroad follows the edge of the sand hills past Ross, Iser, and Polvo sidings. Not far west are extensive fields of cotton, alfalfa, and other crops raised by irrigation, partly by water pumped from the valley fill.

The course of the Rio Grande is very sinuous, and some of the larger bends bring it near the railroad. On the opposite side in Mexico are irrigated areas and in places large mountains, which seem close. There are many cottonwood trees along the valley, and for a while in the summer the air is filled with their seeds by fluffy tufts of cotton.

Tornillo⁸⁸ (tore-nee'yo) is a small village sustained by cotton raising and other agricultural interests. Fabens, 6 miles beyond it, is a town of considerable importance in the center of a large and prosperous irrigation community.

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⁸⁸This name is used for a "screw bean" plant (Strombocarpa pubescens), common in the alluvial valleys of this region. The plant is similar to mesquite but bears a twisted bean that contains considerable sugar.

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The contrast here is very great between the sandhill and desert country of the terrace just north and the fertile irrigated district in the bottom lands. About 20 miles north of Fabens, in places visible from the railroad, is the south end of the Hueco Mountains (way'co).⁸⁹

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⁸⁹This range presents a succession of strata. from Permian limestone at the top through limestones of Pennsylvanian and Mississippian age, Silurian (Fusselman limestone), Ordovician (Montoya and El Paso limestones), and Upper Cambrian (Bliss sandstone). A coarse pink granite crops out in places, apparently underlying the Bliss sandstone. In the south edge of the area the limestone of Permian age lies directly on Montoya limestone. A typical section is shown in Figure 25. Farther north, in the western portion of the mountains, there are extensive exposures of Carboniferous, Silurian, and Ordovician strata. Here in places the Permian has a red conglomeratic member at the base lying unconformably on limestones of Pennsylvanian age. These relations are well exposed in Powwow Canyon on the highway from El Paso to Carlsbad. The lower beds of the limestones regarded as Permian carry abundant remains of the foraminifer Schwagerina uddeni.

FIGURE 25.—Section through the south end of the Hueco Mountains, 20 miles north-northeast of Fabens, Tex. Cp, Limestone (Permian); Cm, limestone (Pennsylvanian and Mississippian); Sf, Fusselman limestone; Om, Montoya limestone; Oe, El Paso limestone; €b, Bliss sandstone.

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Clint is a local center for a productive irrigation district which extends to and beyond El Paso. In this district the railroad passes through irrigated fields of alfalfa and many other crops, gardens, and orchards. One of the large ditches here parallels the railroad for several miles. Most of the roads in this district are "alamedas" (ah-lah-may'das) embowered by overarching cottonwood trees.

In this portion of the valley a few hundred Indians still remain, mostly working on ranches or associated with Mexican settlements. Originally they had many rancherías of their own. They were of the Pueblo type and known as the Tiguas (Teguas or Turcervas). Of the many Indians formerly in Texas probably not more than 2,100 remain, widely scattered in small groups, the largest of which is in Polk County, in the east-central part of the State.

The old Mexican village of San Elizario, 2 miles west of Clint, was once the seat of Spanish government of the territory of Nuevo Méjico. The viceregal residence is still standing opposite the old church and jail. The place is famous also as the center of the "salt war" of 1877, initiated by the earlier settlers, who rebelled at paying for salt in Salt Flat (see p. 117), and also as the scene of some of the exploits of the outlaw known as "Billy the Kid."

Ysleta (ees-lay'ta) is one of the old settlements of the Rio Grande Valley, now largely Mexican in population but originally Indian. Its cathedral is the old Spanish mission of Nuestra Señora de Carmen, founded in 1682 shortly after the Indian rebellion of 1680.

From Ysleta into El Paso there is a wide zone of almost continuous settlement with attractive residences, shade trees, and irrigated fields, gardens, and orchards raising hay, alfalfa, and other forage crops, vegetables, fruits, and other products for the local market and for shipment. Long-staple cotton is also an important crop here, yielding a bale to the acre. After the long trip through the thinly populated arid part of western Texas this irrigated valley seems like a different country. About 180,000 acres is under cultivation above and below El Paso. With an average annual rainfall of only 9 or 10 inches irrigation is absolutely necessary. The water is taken from the river, which has furnished it for several centuries, but now the Elephant Butte Reservoir, 115 miles above El Paso, insures a regular and larger supply.

Near El Paso there are fine views of the Franklin Mountains, to the northwest, and some prominent ranges in Mexico, to the west and southwest.

The railroad enters El Paso from the southeast and goes to a union station near the western edge of the city. El Paso is a large, long-established business, livestock, and railroad center, an important port of entry from Mexico, and the headquarters of the large Army post of Fort Bliss. Its original site was determined by the gateway cut by the Rio Grande and a good ford crossing into Mexico. It is on "El Camino Real" (ca-mee'no ray-ahl'), now Highway 85, the oldest highway on the continent, which passes through the city as San Francisco Street.

The Rio Grande was discovered in 1536 by Cabeza de Vaca, who, after eight years' wanderings following the disastrous failure of the Narváez expedition to Florida, forded the river just above its junction with the Rio Conchos, 100 miles below El Paso. It seems probable that De Vaca reached the El Paso region in 1536 and traveled up its east side far north into the present New Mexico before turning southwest to reach Culicán, in Mexico. (Sayer, Bolton, and R. T. Hill.) It was next visited in 1540, in its northern extension, by Hernando de Alvarado, one of Coronado's captains, who named it the Rio Bravo del Norte, a name still in use on most Mexican maps.

The first explorers to cross the ford at El Paso were Francisco Sánchez Chamuscado with Padre Agustín Rodríguez in 1581, and Antonio de Espejo the next year. They had both ascended the Rio Grande, which they called the Guadalquivir (gwa-dal-kee-veer'), from the mouth of the Rio Conchos. In 1598 Juan de Oñate reached the Rio Grande 25 miles below El Paso with a band of heroic colonists consisting of 130 soldiers or more, most of them with their families, with 83 wagons and 7,000 cattle. This expedition crossed the river at El Paso and took possession of all the region to the north in the name of King Philip II of Spain, calling it Nuevo Méjico. Oñate then ascended the Rio Grande Valley to the mouth of the Rio Chama, in New Mexico, where his colony was established under the name of San Juan de los Caballeros. The headquarters of this Spanish colony was subsequently removed to Santa Fe, and it was from that place, at the time of the pueblo rebellion in 1680, that about 1,000 settlers and some loyal Indians fled down the valley to the mission of Nuestra Señora de Guadalupe, started by the Franciscans in 1659 on the south side of the river, at the present Ciudad Juárez (seeyou-dahd' hwah'race).⁹⁰ This incident led to the establishing of a presidio (fort) and supply station at the mission, which was the beginning of settlement in the general El Paso region. Twelve years after the revolt Diego de Vargas left El Paso and effected an easy reconquest of the Pueblo Indians.

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⁹⁰Named for the liberator Benito Juárez, first President of Mexico, who at one time had the capital there.

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In 1700 the settlement at the ford had a population of 5,000, including 637 Indians, and the white inhabitants of the whole territory numbered perhaps 19,000 and the Indians 10,000. The place had a large traffic, especially in January, when an annual fair held in Chihuahua was attended by New Mexican traders, at times numbering 500. The neighborhood was famous for its orchards and vineyards, supported by irrigation from a dam, which was usually destroyed by each summer's floods. Zebulon Pike was the first English-speaking person to visit the place, having been taken there in 1807 as a prisoner by Spanish forces. At this time there was no settlement on the north side of the river, but the sites of the Mills Building and the Southern Pacific station in El Paso were occupied by the adobe buildings of the hacienda of a Mexican named Ponce de Leon. On his death in 1857 it came into American hands, the first owner being Franklin Coontze, after whom Mount Franklin is named. About that time James Magoffin, whose diplomacy had secured for the United States the acquisition of New Mexico from Mexico without the firing of a single shot, established a trading post near by which was called Magoffinsville. Fort Bliss, a short distance northeast, was started by the United States Government in 1848 for the protection of the frontier. The region was generally referred to as El Paso (the pass).

In 1852 a post office, called Franklin, was established here, and in 1859 this name was changed to El Paso. There was no town development until after the Civil War—in fact, there was no settlement between Fort Clark and the El Paso region, a distance of 480 miles. There was continuous traffic, however. Three mail routes afforded communication with Santa Fe, San Antonio, and San Diego (see p. 97), and San Francisco. From 1858 to 1861 the Butterfield Overland Mail transported mail semi-weekly from St. Louis and Memphis to San Francisco under contract at $600,000 a year. The annual receipts reported from this line in 1859 were $27,230. The railroad was used to Tipton, Mo., and stage coaches the rest of the way. The time, consumed was 21 to 23 days, and the passenger fare was $150 and $200, without meals. This mail service was transferred to a more northerly route in 1861, and soon after that the Civil War cut the seceded States off from the United States postal service. A few years after hostilities ceased a triweekly schedule was established for this region. The railroad reached El Paso from the east in 1883 and in the next few years brought many immigrants to the Rio Grande Valley. Since that time the city has had a rapid growth.

El Paso has long been prominent as a headquarters for the mining industry, although there are no notable mines in its immediate vicinity. For many years it has had the largest custom smelter in the United States, usually employing 1,000 men and treating ore from New Mexico, Arizona, and Texas. (See pl. 18, A.) In 1930 the Nichols copper refinery was completed on the eastern edge of the city. Just west of this refinery are the Pasotex and Texas Co. oil refineries, which receive crude oil by a long pipe line from the Winkle field in Texas. Another pipe line brings gas to El Paso. The large cement plant on the western edge of the city furnished the cement for the Elephant Butte Dam; it utilizes the limestone of the Comanche series.⁹¹ Beaumont Hospital is a large Government establishment for tubercular soldiers, and Fort Bliss, 5 miles northeast of the center of the city, with 153 officers and 2,362 men (in 1930), is the largest cavalry post in the United States. The Texas College of Mines, a branch of the University of Texas, and Loretto College or convent are also in El Paso. The city water supply is obtained from a group of deep wells, which are reported to yield 14,000,000 gallons a day.

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⁹¹Cement is made by roasting a mixture of ground limestone and shale and grinding the resulting "clinker" to a fine powder. In some places clay is used instead of shale. Some limestones contain naturally a suitable admixture of the clay element for the manufacture of hydraulic cement. Most limestones could be utilized for cement manufacture, but there is a limit to the demand, and it is difficult to introduce a new brand of cement in competition with cements of established reputation which have proved their uniformity and reliability by many tests. The items of cheap fuel and local market are important considerations in making cement.

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PLATE 18 A (top), SMELTER AT EL PASO, TEX. Receives large amounts of gold, silver, copper, and other ores mined in the Southwest. The mountains in the background are in Mexico. B (bottom), KILBOURNE HOLE, A GREAT CRATER IN THE TERRACE PLAIN IN NEW MEXICO WEST OF EL PASO, TEX. Believed to be a result of steam explosion. Looking south. There is a ranch near center of hole.

The climate at El Paso is typical of that in much of trans-Pecos Texas. The mean annual precipitation is slightly less than 10 inches, with a recorded range from 2.22 to 18 inches. Most of the rain falls in heavy local showers, and more than half of the annual total comes in July, August, and September. The greatest recorded fall was on July 9, 1881; it amounted to 6-1/2 inches. The mean annual temperature is 63.5°, and the mean monthly minimum about 31° in January. The temperature is rarely below 20° and then only for a few hours. The average humidity ranges from 23.2 per cent in May to 47.3 per cent in January, with an average of 39 per cent for the year. The annual evaporation is estimated at 82 inches. Snow falls rarely and then only in small amount, and usually it melts in a few hours. The percentage of sunshine is about 81.

Outside of the irrigated zone the vegetation is characteristic of an arid climate. Trees are rare, even on the mountains, but there is a scattered growth of mesquite and creosote bush (Covillea). Yucca, lechuguilla, sotol, bear grass, ocotillo, and several species of cactus are abundant on the slopes.

In New Mexico and Texas above El Paso the Rio Grande flows in a wide valley of alluvium, bordered by a high older terrace plain; in parts of its course farther north in New Mexico it is in deep rocky canyons. At El Paso the valley is constricted to the narrow rock-walled pass that gives name to the city, but the bordering high terrace continues far down the valley. Below the pass the alluvial plain is a broad flat in which the river meanders widely, often changing its course by cutting new channels at times of freshets. The high terrace plain that borders this valley terminates in bluffs and steep slopes, in places 200 feet high above the bottom lands. The smooth plain at the top of these bluffs extends far north as a wide bolson or desert flat between mountain ranges. Near El Paso there are several distinct benches, 3,800 to 3,950 feet above sea level, mostly in the form of mesas or projections from the base of the Franklin Mountains. These benches slope gently toward the river and are in part capped by caliche, an infiltration of calcium carbonate in the sand, which makes a material so hard that it helps to preserve the tabular form and sharp edges of the mesas. The Franklin Mountains form a high ridge on the southern prolongation of an axis of uplift which extends across central New Mexico from the Rocky Mountains. Probably this uplift is cut off to the south by a fault. The range rises abruptly about 3,000 feet above the adjoining plains or valleys and culminates in Mount Franklin (elevation 7,152 feet). The west side is mainly a dip slope of heavy beds of limestone with pronounced westerly dip; the east side shows many ridges, irregular lower crests, and buttes, deeply cut by canyons. The range is a typical tilted block of the basin-range type, which predominates in a large part of the Southwest.⁹²

The huge "M" so conspicuous on the mountain side is painted each year by the students of the School of Mines; the "E" is placed there by high-school students. At night a flashing beacon to guide airplanes is a noticeable feature on the south end of the mountain. The mountains to the south, in Mexico, are the Sierra Guadalupe and the Cerro de Muleros.

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⁹²The Franklin Mountains present a fine succession of strata from pre-Cambrian to Permian, all so bare and free from talus that the various formations are easily studied. They have been described by Richardson. The section in Figure 26 shows the principal features of the range, and the formations are listed in the following table:

Formations exposed in the Franklin Mountain area

Age	Formation		Thickness (feet)
Lower Cretaceous (Comanche).		Limestone, shale, and sandstone.	300
Permian.	Hueco.	Limestone.	1,500
Pennsylvanian.	Magdalena.	Limestone.	0-100
Devonian.	Percha.	Limestone, dark, impure.	40
Silurian.	Fusselman.	Limestone, massive, light and dark.	1,000
Ordovician.	Montoya.	Limestone, massive, magnesian.	20-400
	El Paso.	Limestone, gray, largely slabby; weathers light.	1,000±
Cambrian. Algonkian(?).	Bliss.	Sandstone, brown and gray, locally conglomeratic at base.
		Rhyolite porphyry, mostly red, with agglomerate at base.	1,500±
	Lanoria.	Quartzite, light and dark, cut by diabase dikes and sills.	1,800+

FIGURE 26.—Section across the Franklin Mountains north of El Paso, Tex. After Richardson. ln, Lanoria quartzite; rhp, rhyolite porphyry; €b, Bliss sandstone; Oep, El Paso limestone; Om, Montoya limestone; Sf, Fusselman limestone; Ch, limestone, mostly Permian, underlain by Devonian and Pennsylvanian to the north; Kcm, Comanche series; gr, granite; Tap, andesite porphyry; Qb, bolson deposits

Granite similar to the pre-Cambrian basement of other regions also underlies the Bliss sandstone, but as some of it cuts the Algonkian(?) and Paleozoic strata all has been classed as post Paleozoic.

The Lanoria quartzite, with its sills of diabase, strongly suggests the Apache group of Arizona and is somewhat like part of the Millican formation near Van Horn. The El Paso limestone here is in its type locality, and the few fossils found in it, to a horizon within 100 feet of the bottom, are of Lower Ordovician age. Locally it lies directly on the pre-Cambrian rocks, but at most places it is underlain by the Bliss sandstone. There are fine exposures of this limestone on and near the roads at the south end of the Franklin Mountains. The Montoya limestone, which contains fossils of the Richmond fauna, is separated from the El Paso limestone by a hiatus representing much of late Ordovician time. The Fusselman limestone, containing a characteristic Pentamerus of Niagaran age, represents but small part of Silurian time. It is 1,000 feet thick and constitutes some of the highest summits in the Franklin Mountains. A small wedge of Devonian strata occurs in the northern portion of the range and also limestone containing Pennsylvanian fossils. The main mass of Carboniferous limestone in the range is, however, of Permian age.

Formations of Cretaceous age crop out near the south end of the range and on its western slope east of Montoya siding. The most extensive exposures are in the quarries that supply the cement works, where about 90 feet of hard massive gray limestone of the Comanche series is exposed. Higher Cretaceous beds appear on the opposite side of the Rio Grande. These strata are invaded by masses of porphyry which have been intruded in a molten condition. At several localities in the western part of the city there were formerly small outcrops of dark fissile shale that carried remains of Inoceramus labiatus, a characteristic Colorado fossil (Upper Cretaceous.) This shale also crops out on the south side of the river. The heavy deposits of gravel and sand of the higher terraces are well exposed in the upper part of the city.

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Wells in El Paso are reported to have penetrated valley fill to the depth of 2,285 feet. Fossil bones found in the Quaternary deposits have been determined as Elephas columbi, Equus complicatus, and Tapirus haysii?, representing an elephant, an ancient horse, and a tapir, all of which have been extinct for many centuries.

Tin ore was discovered in the Franklin Mountains in 1899, and various unsuccessful attempts have been made to work it profitably. The mineral is cassiterite, or tin oxide, and it occurs with quartz in the granite 12 miles north of El Paso.

The Franklin Mountains figure in many legends of the Indians and early settlers. One of the peaks suggests the outline of an Indian's head, traditionally said to be that of Cheetwah, a chief who was responsible for the massacre and exile of the Spaniards in New Mexico in 1680. There also is the reputed location of La Mina del Padre, a famous lost mine, the entrance to which, so the story runs, can be seen from the portal of the cathedral in Juárez by looking northeast exactly at sunrise "on the right day of the year."

In the Hueco Mountains, above the long talus slopes, there are caves which have yielded remains of the primitive people who once inhabited the region—fragments of headdresses, sandals, a cord skirt, and shell pendants, possibly indicating a ceremonial place. At Hueco Tanks are pictographs of various life forms and geometric designs in red pigment, and at the foot of the range near the New Mexico State line are the ruins of a pueblo of considerable size.

The Southern Pacific lines enter New Mexico on crossing the Rio Grande just west of El Paso, the State line being at midstream. This is actually in the western half of the State, the east boundary being meridian 103°, which is crossed by the railroad east of Alpine. The width of New Mexico is nearly 352 miles, and its greatest length from north to south is a little more than 390 miles. It covers an area of 122,634 square miles, or slightly more than that of Colorado. It includes the south end of the Rocky Mountains, the general axis of uplift of which extends to El Paso, together with wide plateau areas in large part higher than 5,000 feet above sea level. The portion east of the Rio Grande was included in the Republic of Texas, and for relinquishing it and some other territory in 1850 Texas received $10,000,000. The rest of the State was acquired by the Mexican War and the Gadsden Purchase. (See p. 150.)

New Mexico was the most highly valued of the Spanish possessions in this country. It was first visited⁹³ by Friar Marcos de Niza, accompanied by the negro slave Estevan, in 1539, in their trip to the vicinity of the Indian pueblo of Zuñi, in search for the fabulous "Seven Cities of Cibola." In the following year Niza led Coronado to the Zuñi villages, where they arrived July 10. Later the Coronado expedition crossed the northern part of the State on a journey to Quivira. The first attempt at colonization was made at the mouth of the Rio Chama in 1598, and later at Santa Fe, by Juan de Oñate. (See p. 124.) It was terminated by the great pueblo rebellion of 1680, however, which forced the settlers (to the number of 1,000) to flee to El Paso, on the south bank of the Rio Grande, where a Franciscan mission had been started in 1659. Here their leader, Antonio Otermín, was successful in having a presidio, or fort, established. The reconquest of the region to the north was begun in 1692 by Diego de Vargas, and the next year recolonizing was again in progress. The region around Santa Fe became an important trading center. Each summer a fair was held at Taos at which furs and other products were obtained from the Indians by the traders in exchange for goods brought from the great annual winter fair in Chihuahua, where Indian products were in great demand. The main line of travel was along the Rio Grande, but after the winning of independence by Texas and the Mexican War great caravans came from the east over the Santa Fe trail.

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⁹³ It seems probable that Cabeza de Vaca may have reached the general locality of El Paso late in 1535, but he ascended the Rio Grande and crossed southwestern New Mexico on the way to Culicán, in Mexico (Bolton, Sauer, and R. T. Hill).

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When first organized as a Territory of the United States in 1850, New Mexico included the area which later became Arizona. It was given statehood in 1912. Its population in 1930 was 423,317 and the density of population 3-1/2 persons to the square mile, having much more than doubled since 1890. More than half of the population are "Mexicans," a people consisting largely of descendants of Mexican settlers of long ago, together with many recent immigrants from Mexico, mostly of the peon class and largely of Indian origin.⁹⁴ Spanish is the language of a large proportion of the population of New Mexico, in many sections greatly preponderating over English.

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⁹⁴Gamio, Manuel, Sources and distribution of Mexican immigration into the United States, Mexico, 1930. Hoover, G. E., Our Mexican immigrants: Foreign Affairs, vol. 8, pp. 99-107, 1929.

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A large number of Indians live in the several reservations, aggregating 7,340 square miles, in the northern and central part of the State. According to the report of the United States Commissioner of Indian Affairs the number was 28,736 in 1932, more than half of them Navajos. There are numerous ruins of settlements of aborigines, some of them of great antiquity, for there were large villages of these people at many places long before the coming of the Spaniards. Irrigation was extensively practiced by some of these ancient people.

According to the Census Bureau and the General Land Office the area of New Mexico is 78,401,920 acres, of which 14,383,995 acres (1931) is unreserved public land, 14,000,000 acres State land, 30,822,034 acres in farms and ranches, and 9,912,026 acres in national forests. Large numbers of cattle, sheep, and goats are pastured in the national forests at a small fee, under certain restrictions as to number of animals and their distribution to avoid overgrazing. About 12,000,000 acres, some of it in ranches, is included in land grants and Indian reservations.

About 2,000,000 acres is cultivated; of these 600,000 acres is under irrigation. The largest reclamation project is that of the Elephant Butte Dam, where the Rio Grande is impounded. The Pecos River is dammed near Carlsbad, and there are many small irrigation projects. United States census reports show that in 1929 the farms and ranches numbered 31,404, with a total value of $220,856,219, including buildings, fencing, and machinery, and the value of crops was $34,648,000. Much of the ranch land and other areas is used as pasture for livestock. Cattle in 1930 numbered 1,060,327, and goats and sheep numbered 2,587,600 and yielded wool and mohair valued at $3,392,114. A large part of the public land in New Mexico is not suitable for agriculture on account of its configuration and the aridity of the climate.

The principal mineral resource of New Mexico is coal, which occurs in large fields west of Raton, near Cerrillos, and about Gallup, also in several minor areas, all in the northern part of the State. The total area underlain by coal is very great. Its production in 1930 was 1,969,433 tons (U. S. Bureau of Mines). There are mines of gold, copper, silver, lead, zinc, and other minerals, and a small production of clays, gypsum, and building stones. Potash is now being mined near Carlsbad, and petroleum and natural gas are obtained in the southeast corner of the State and in the San Juan Basin. According to the Bureau of Mines the values of metals produced in 1929 were, copper, $18,000,000; zinc, $4,520,000; lead, $1,397,000; silver, $582,000; and gold, $707,000—in all, $25,206,000. The yield of petroleum in 1929 was 1,830,000 barrels; in 1931 it was 15,360,383 barrels, mostly from Lea County, and a large amount of natural gas.

The climate of southwestern New Mexico is in general similar to that of areas of like elevation above sea level (4,000 feet or more) in a wide region extending from western Texas to southern California. The winters are mild, and although the summers are hot the air is so dry that the heat is much more endurable than in the sultry periods that occur in the summers of the Eastern and Central States. December is usually the coldest month, with an average temperature of about 40°. On nearly 300 days in a year there is sunshine for the greater part of the day, and storms of long duration are rare. The region lies outside of the normal storm track that extends over the central United States, and in consequence the weather is much more uniform than in the regions farther north and east. The principal rainy season is in July, August, and September. The annual rainfall in the wide valleys is mostly less than 10 inches, but on the higher ridges there are many rains and snows at times when there is little or no precipitation in the adjoining desert valleys.