of the Gila river and W. of the Rio Grande. Here volcanic activity and powerful erosion have combined to produce a series of remarkable scenic effects. The eastern border of this area is formed by the valley of the Rio Grande and the western foot-hills of the Rocky Mountains; the southern boundary overlooks the Gila river; and on the N. and W. the plateau continues into Colorado, Utah and Arizona. Near its southern and eastern borders are many lava flows and extinct volcanic mountains, one of the most imposing of those in New Mexico being the Mt. Taylor volcano (11,389 ft.), which is surrounded by lava tables and some of the most wonderful volcanic buttes in the world. In other portions of New Mexico there is also much evidence of former volcanic activity. A conspicuous feature of the New Mexican landscape is the mesa, a flat-topped hill created by differential erosion and projecting above the surrounding country like a table. A notable example is the mesa of Acoma, in Valencia county, capped with volcanic rocks; upon its summit, about 350 ft. above the plain, is the Indian pueblo of Acoma.
The average elevation of New Mexico is 5700 ft., with 40,200 sq. m. between 3000 and 5000 ft.; 56,680 sq. m. between 5000 and 7000 ft.; 22,500 sq. m. between 7000 and 9000 ft.; and 2000 sq. m. above 9000 ft.
For a region with such a small amount of rainfall the rivers are numerous, but none of the streams is navigable, and in many of them during the dry season (and in some of them because of broken stratification) the water in places disappears entirely beneath the sandy bed, and after flowing underground for some distance, breaks out afresh farther on as a river, rivulet or spring. The most important stream is the Rio Grande, which, rising in southern Colorado, enters New Mexico through deep canyons near the centre of the northern boundary and continues southward across the entire state. During its course it changes from a mountain stream in the N. to a sluggish river turgid with sand in the S. In the lowlands it loses much of its volume through evaporation and absorption by the sands, and through irrigation, and in its lower course in New Mexico its bed is frequently dry. In the flood season it usually leaves its banks and inundates the lowlands, spreading over the sands a rich deposit of silt; and on account of this characteristic it is sometimes called “the Nile of New Mexico.” The stream next in importance is the Pecos river, which rises in Mora county and flows southward into Texas, where it joins the Rio Grande. It has the same general characteristics as the latter river, being a mountain stream near its source, and after leaving the highlands becoming sluggish and losing much of its water. Along the lower course many underground streams from the mountains break out as springs and empty into the Pecos. The Canadian river drains the eastern slope of the Rocky Mountains and flows in a general south-easterly direction through Texas into Oklahoma, where it empties into the Arkansas. Most of its course in New Mexico lies through a canyon. The westward-flowing streams—the San Juan, Rio Puerco of the West, Zuñi, Rio San Francisco and Gila—are of only slight importance, though their flow is perennial. In the valleys there are many small streams whose waters never reach the ocean, but disappear by seepage or evaporation.
Fauna and Flora.—Of native animals the species are numerous, but their numbers are small. Bison no longer roam the plains, and the elk has been driven out; but among the larger mammals still to be found in certain districts are the deer, prong-horn (in small numbers), puma, coyote, timber wolf, lynx (Lynx rufus and Lynx Canadensis) and the black and grizzly bear. Badgers, hares and rabbits are found everywhere, and prairie-dogs are so numerous in some places as to be considered a nuisance. There are numerous species of aquatic birds. From time to time upon the Rio Grande may be seen ducks, wild geese, swans, cranes, herons and gulls. Eagles are often seen, and in the arid and elevated regions crows and ravens are numerous. Gamble’s quail, bob-white, grouse, English pheasants and wild turkeys are the most important game birds, and the mocking-bird is common throughout south-western New Mexico. Among the venomous reptiles and insects are the rattlesnake, the Gila monster (Heloderma suspectum), a poisonous lizard, and the tarantula (Mygale Heintzii), which, however, are common only in certain places and at certain seasons.
New Mexico has such a great range of elevations that all four of the zones of vegetation into which the South-West has been divided according to altitude are found within its limits; namely, the zone of cactus, yucca and agave (3000–3500 ft.), where grass is scanty; the zone of greasewood and sage-brush (3500–4900 ft.), where there is little grass, and the cactus species are less numerous; the zone of the cedar (4900–6800 ft.); and the zone of the pine and fir (6800–10,800 ft.), in which grass is more abundant. The total woodland area has been estimated at 23,700 sq. m., or a little more than 19% of the land area. Only the higher ranges and plateaus are timbered, and even there the forests are not dense. The lower slopes are usually covered with the scrub oak, juniper and piñon; but some mountains, especially those along the eastern border of the Rio Grande Valley, are absolutely treeless. The principal forest areas are upon the southern end of the San Juan Range, upon the Sangre de Cristo Range and in Socorro county, W. of the Rio Grande. The chief varieties of timber are the red fir, Engelmann’s spruce and yellow pine. Up to 1910 the Federal government had created eleven forest reservations in New Mexico, embracing an area of 10,971,711 acres. In the valleys the only trees native to the soil are the willow and cottonwood, found along the water courses, and beyond the range of irrigation vegetation is limited to scanty grass, with sage-brush and greasewood in the N. and cactus and yucca in the S.
Climate.—As the winds that reach New Mexico have been desiccated while crossing the plains of Texas or the mountains of the N.W., the climate is characterized by a lack of humidity. The sandy soil quickly absorbs the sun’s heat and also quickly radiates it, so that there is great daily variation in the temperature. The low humidity, high altitudes and southern latitude all combine to make the climate salubrious and especially beneficial to persons suffering with pulmonary disorders. The highest temperature ever recorded was 110° F. at Roswell; the lowest, −23° at Aztec. At Santa Fé, where mountain and plain meet, the mean annual temperature is 49°; the mean for the winter is 31° and for the summer 67°; and the highest and lowest temperatures ever recorded were respectively 97° and −13°. At Fort Bayard, in the S.W., the mean temperature for the year is 55°; the mean for the winter is 39°, with an extreme recorded of −1°; the mean for the summer is 72°, with a maximum recorded of 103°. At Mesilla Park, in the lower Rio Grande Valley, the mean annual temperature is 60°; for the winter it is 43°, with a minimum of 1°, and for the summer 77°, with a maximum of 106°. In all parts of New Mexico except the N.W. there is a so-called wet season, which begins early in July and lasts for a month or six weeks, the rain coming in the form of short afternoon thunderstorms. About a third of the precipitation occurs during July and August, but after August the monthly precipitation is steadily less until March, in which month only about 3% of the annual rainfall occurs. For all of New Mexico the mean precipitation is about 13 in., ranging from 9 in. in the lower Rio Grande Valley to 25 in. on the mountain ranges at elevations of 10,000 ft. and over. In the valleys there are usually about two snows a year and these quickly disappear; but on the mountain peaks and in the canyons the snow accumulates to great depths and forms a steady source of water-supply for the rivers. It is the melting of the snows on the Rocky Mountains, and not the rainy season, that produces the floods of the Rio Grande.
Soils.—The prevailing type of soil on the higher lands is a sandy loam, underlaid with clay or clay loam, which stores water and is the typical soil of the basins. Along the river valleys there are limited areas of fine sediment, and here with irrigation good crops can be grown without the use of fertilizers. In the plains where drainage is poor, especially in the S., the soils contain too much alkali; but in the highlands most of this has been dissolved and carried away by the rains, and the soils are well adapted for grazing grounds.
Agriculture.—Because of the small amount of rainfall, agriculture is confined chiefly to the river valleys. In 1900 only 4·2% of the land surface was included in farms, and less than ·27 of 1% was classed as improved farm land. The total acreage, however, rose from 787,882 in 1890 to 5,130,878 in 1900, an increase of 551·2%. Between 1850 and 1880 there was very little increase in farm area. The amount of improved land, though showing an absolute increase between 1880 and 1900, declined relatively to the total area in farms from 37·6% in 1880 to 6·4% in 1900. At the same time the average size of farms (not including farms with an area of less than 3 acres, which reported an annual income of less than $500) increased from 124·9 acres in 1880 to 433·6 acres in 1900. This decrease in the proportion of improved acreage and increase in the average size of the farms is due to the increased use of lands for grazing purposes. As regards tenure, 90·6% of the farms in 1900 were operated by owners, 2·2% by cash tenants, and 7·2% by share tenants. In this year 39·6% of the farms derived their principal income from hay and grain, 33·2% from live stock, 5·5% from dairy produce, 3·5% from vegetables, 2·8% from fruits. The most important crop, as a result of irrigation, is alfalfa, which is grown for forage, requires little attention, and improves the soil. Wheat, Indian corn and oats are the leading cereal crops; and S. of the latitude of Santa Fé vegetables and deciduous fruits flourish where the water-supply is ample. A little cotton has been grown near Carlsbad in the Pecos Valley, and in 1909 sugar beets were introduced south of Albuquerque and cantaloupes in the southern Rio Grande Valley. Fruit, especially the Bartlett pear, is very successful. The total value of farm property in 1900 was $53,767,824, and the value of the live stock, $31,727,400. The value of the farm products in 1879 was $1,897,974, in 1889 $1,784,824, and in 1899 $10,155,215. In 1909 the values of the principal farm products (according to the Year Book of the U.S. Department of Agriculture) were as follows: hay, $5,339,000; wheat, $1,175,000; Indian corn, $1,915,000; oats, $634,000; and potatoes, $86,000. The values of the various classes of live stock on the 1st of January 1910 were as follows: sheep, $13,714,000; milch cows, $1,125,000; other neat cattle, $15,677,000; horses, $6,251,000; mules, $632,000; swine, $272,000. Stock-raising is the most important industry, and the growing of sheep for wool takes a leading place. The hills and mesas covered with the nutritious grama grass form excellent grazing grounds, which are most extensive in Bernalillo, Guadalupe, Rio Arriba, San Miguel, Union and Valencia counties. In April 1907 (according to an estimate of the National Association of Wool Manufacturers) New Mexico contained 2,600,000 sheep, the largest
