Part 9

Completing the circuit of the Big Room and returning to the lunchroom, visitors may either walk or board an elevator and ride smoothly back to the surface.

How were the Caverns formed? The story began about 240 million years ago, during the Permian Period. At that time, the two limestone formations in which the caverns occur—the Tansill Formation and Capitan Limestone—were deposited as part of an organic reef complex at the edge of a warm shallow sea.

During subsequent periods, other seas brought in sedimentary material that covered the reef. About 60 million years ago, earth movements, which were responsible for the uplift of the area, fractured the reef and permitted surrounding ground water to enter along fracture lines and begin work in fashioning the caverns. The water at first dissolved small crevices in the limestone. As more water came in, the crevices enlarged to cavities, called solution pockets. Then the walls, floors, and ceilings of the pockets dissolved and collapsed, joining the pockets, while the solution process continued, eventually forming the huge rooms seen today.

Beginning about 3 million years ago and into recent times, the uplift of the local Guadalupe Mountains and changing climates lowered the water table. Water that had been inside the caverns drained away and was replaced by air. Most solution stopped, but large sections of partly dissolved walls and ceilings collapsed under their own weight. Stability was finally achieved, however, and probably no rock has fallen within the caverns during the last several thousand years.

Even before the collapsing ended, another phase of cavern development had begun. Rain water and snow melt slowly seeped into the caverns. Droplets of water, each holding a minute quantity of dissolved limestone, appeared upon the ceilings. Exposed to the air, the droplets evaporated and left their mineral content as calcite and aragonite—crystalline forms of limestone. Over centuries, this process of evaporation and deposition has built a myriad of crystalline stalactites of all shapes and sizes. Water that dripped to the floor evaporated and deposited the calcite and aragonite to build stalagmites. When joined together, stalactites and stalagmites become columns, or pillars. In the scenic rooms, conditions existed that brought about the creation of helictites—twisted formations that seem to defy gravity in their growth. Color in the cave formations, shades of brown, red, and yellow, result from the presence of small amounts of iron oxide and other minerals.

Carlsbad Caverns National Park offers more than the caverns themselves. Each evening from April to October, bats in incredible numbers spiral upward out of the Caverns’ entrance and fly southward over the rim of the escarpment to feed in the valleys of the Black and Pecos rivers. They return just before dawn, diving swiftly and from high altitudes into the entrance. Flying directly to the bat cave, they spend each day hanging head downward in dense clusters from the walls and ceilings. The bat cave itself is not open to visitors. A park naturalist explains the bat flight and discusses the bats in detail in a talk given at the entrance to the Caverns each evening before the flight begins.

The nature trail, a half mile loop that begins and ends near the entrance to the Caverns, guides the visitor to many of the desert plants of the region. The park is visited by more than half a million people each year, and yet the delicate cave formations and the natural beauties remain unmarred.

White Sands National Monument

White Sands National Monument, fifteen miles southwest of Alamogordo, is another area of great interest to the geologist and biologist. But its strangeness, the graceful contours of its snow-white dunes, and the peculiar adaptations of some of the plants and animals that live among its dunes are appreciated as fully by the nonscientist. More than 370,000 visitors come to marvel at the White Sands each year.

The Monument, some 230 square miles in extent, preserves the most impressive part of the world’s largest gypsum desert. This is a glistening sea of pure gypsum sand that the wind has drifted into huge dunes that are almost bare of vegetation except along the fringes. Wavelike, the restive dunes move slowly before the prevailing winds, covering and uncovering the few plants that lie in their way. And wavelike, their surfaces trace the vagaries of indecisive breezes in tiny parallel ripplelike ridges.

Because of the almost constant wind and resulting gradual advance of the dunes, most of the plants that are able to establish themselves in the open flats between the dunes eventually become buried. A few species, however, are able to survive the irresistible march of the sand. Through rapid growth and elongation of the stems, the struggling crowns remain on top of the rising crests of the dunes. Plants with stems more than forty feet long have been found. As the dunes continue forward under the pressure of the wind, they leave the plants elevated on columns of compacted gypsum bound by their adventitious roots.

Animals, too, have become adapted to their unusual surroundings. The small creatures, lizards, mice, and others, are picked off easily by such predators as foxes, coyotes, and hawks when they are conspicuous. Thus, through the centuries, only the lighter-colored individuals have survived among the dunes and, through many generations, have developed pale and elusive animals that blend inconspicuously with their white surroundings. Pocket mice are a good example of this. Among the white dunes, the pocket mice are white; in the nearby red hills, they are a rusty color; and on the beds of black lava a few miles north of the sand, the pocket mice are very dark.

A visitor to White Sands National Monument should stop at the visitor center, where exhibits explain the geology of the duneland and others describe the plants and animals that are able to live there.

But how and from where did this natural wonder come? The dunes of gypsum lie in the Tularosa Basin, which stretches for more than 100 miles between two north-south mountain ranges. All sides of the valley slope gently inward, forming the basin, with Lake Lucero, its lowest point, at the southwest end of the Monument. This valley was formed hundreds of centuries ago, when a great section of the earth’s crust settled to form the type of basin known geologically as a graben.

High above the basin floor, beds of gypsum are found to the north in the mountain ranges flanking the valley. Similar gypsum beds lie far beneath the floor of the basin. Thus, it was once a part of the high plateau, a great blocklike section that slowly sank to form the basin at its present level.

Percolating water from seasonal rains and melting snow carries tons of gypsum, in solution, from the highlands at the north end of the basin into Lake Lucero. During much of the year, cloudless skies and warm dry winds evaporate Lake Lucero, and it shrinks to a crystal-encrusted marsh. Capillarity draws the gypsum-laden underground water to the surface; it, too, evaporates, depositing its burden of gypsum throughout the extensive “alkali flats.” The persistent southwest wind picks up the particles of gypsum and whirls them away, adding them to the gleaming white dunes, the accumulation of centuries.

The best ways to see the dunes are by car and by foot. Along the drive that leads into the heart of the duneland are numbered posts that correspond to numbered paragraphs in the Monument’s informational folder. These paragraphs explain the features that are of particular significance. At pull-outs along the drive, park the car and walk among the dunes.

Capulin Mountain National Monument

Capulin Mountain National Monument, in the northeast part of the state, is an area of geologic interest that presents still another aspect of the science of the earth. It contains the cone of an extinct volcano, one of the most symmetrical of the geologically recent cinder cones in the United States. Its conical form rises more than 1000 feet above its base. The irregular rim is about one mile in circumference, and the crater is about 415 feet in depth, as measured from the highest part of the rim. Some 40,000 people a year visit the Monument.

The mountain consists chiefly of loose cinders, ash, and other rock debris of volcanic explosions. These materials were spewed out by a series of successive eruptions, probably of considerable duration. The coarse materials fell back around the vent, piling up to form the conical mound. Dust and other fine materials were carried away by the wind. After the eruptions, vegetation gained a foothold on the steep, unstable flanks of the cone, so that in time the slopes became stabilized. Geological studies indicate that the volcano probably was active about 7000 years ago.

Capulin Mountain is of special interest, partly because it represents the last stages of a great period of volcanic activity that was widespread throughout western North America. Evidences of this older and more intense activity can be seen from the top of Capulin Mountain in the scores of other nearby volcanic hills and peaks. The largest of these is the Sierra Grande, an extinct volcano rising 4000 feet above the surrounding plain; it is ten miles to the southeast. Northwest of Capulin are a number of mesas that are capped with black lava, the largest of which are Barella, Raton, and Johnson. Fishers Peak, south of Trinidad, Colorado, is on a similar mesa. The famous Spanish Peaks, northwest of Trinidad, are a pair of extinct volcanoes.

In this great volcanic area, the lava erupted in a succession of flows. The series of eruptions were separated by long periods of inactivity. During these inactive times, erosion cut valleys and wore down parts of the old lava sheets. This action formed new channels and lower terrain over which succeeding lava flows spread. This process was repeated at least three times. The oldest lavas, which have been exposed by erosion, are found on the tops of the highest mesas. The last series of eruptions created Capulin Mountain; they were ejections mostly of cinders and ash, with less lava flow than in the preceding volcanic activity. These cinder-and-ash eruptions were so recent, geologically, that some of the nearby, bare, steep-sided cinder cones appear as if they had just cooled.

The National Park Service has constructed a road up the mountain to the rim of the crater. And from the parking area at the rim, two trails lead to the most interesting points on the mountain. One trail, self-guiding, makes the complete one-mile circuit of the crater along the rim. A guide booklet, keyed to numbered stakes that have been set at places along the trail, explains the features of particular significance—both on the mountain and in the distance. The other trail, less scenic, provides a rare opportunity to see a volcanic mountain from the inside out, for it leads down to the bottom of the crater.

Chaco Canyon National Monument

Rich in areas of geological interest, New Mexico is equally rich in areas of archeological interest. Four of these are preserved as units of the National Park System.

Chaco Canyon National Monument, in the northwestern part of the state, contains more than a dozen large prehistoric ruins and hundreds of smaller archeological sites. These ruins are considered to be without equal north of central Mexico. No other archeological area in the Southwest exhibits such a high development of prehistoric Pueblo civilization. Most of the sites lie within a strip of land about eight miles long and two miles wide, through which Chaco Canyon runs. Although the Monument is relatively isolated, it is open year around and is visited by about 22,000 people annually.

The most imposing and best known of the ruins is Pueblo Bonito. Built between 800 and 900 years ago, this 4- and 5-story village covered more than three acres and contained about 800 rooms and 32 kivas, or ceremonial chambers. Archeologist Neil M. Judd, of the National Museum, who conducted some of the late excavations, has said that Pueblo Bonito was the largest apartment house built anywhere in the world prior to 1887, estimating that at one time it housed 1200 people.

Earliest of the Chaco sites, small villages of crude pit houses were occupied during 600 to 800 A.D. Archeologists, studying changes in masonry style, pottery types, and other remains, have pieced together the development of the culture of the inhabitants of Chaco Canyon over a period of six centuries.

After Chaco Canyon’s cultural high point was reached in the 1100’s, a gradual decline set in. The population decreased, and in the 1200’s, the region was abandoned. During this same century, other Pueblo centers within the San Juan Basin were also deserted.

Various theories have been advanced to explain this exodus: soil erosion, warlike enemies, poor facilities for urban sanitation, drought, and intervillage warfare. One or a combination of these factors might have been instrumental in bringing about the abandonment of the region.

Aztec Ruins National Monument

Aztec Ruins National Monument, at Aztec in the northwestern corner of the state, was set aside to preserve an outstanding example of classical Pueblo construction, one of the largest pre-Spanish villages in the Southwest. More than 40,000 visitors come to the Monument each year.

Tree-ring dates indicate that most of the big central pueblo was rapidly constructed during the period 1106 to 1121. At this time, the people of Aztec were influenced by the cultural center to the south, Chaco Canyon. During the last half of the 1100’s, after the decline of Chaco Canyon had begun, the people of Aztec began to look toward the north, and by 1200, Mesa Verde ideas dominated the region. Aztec was abandoned by about 1300, as was the rest of the general region.

Of particular interest at Aztec Ruins National Monument is the reconstructed Great Kiva. The Pueblo Indians built separate rooms, now known as kivas, for ceremonial purposes. During the period of Chaco influence, the people at Aztec constructed a very large circular building, 48 feet in diameter, in their plaza. Its features differ from those of the small kivas and establish it as a Great Kiva, similar to those at Chaco. The Great Kivas represent the peak of religious architecture among the Pueblos. The Great Kiva at Aztec was completely restored in 1934 by Earl H. Morris, of the American Museum of Natural History.

Bandelier National Monument

Bandelier National Monument, forty-six miles west of Santa Fe, preserves the ruins of dwellings and other structures that were erected by Indians who lived in the area until about 1550 A.D. Almost 100,000 people visit the Monument each year.

When many of the ancient Pueblo Indian centers were abandoned in the late thirteenth century, the people moved to locations where the water supply was more constant. A favorable area was the upper Rio Grande Valley in what is now New Mexico. One of the later flowerings of Pueblo culture occurred here. The ruins within Bandelier are representative of this phase of Pueblo development.

In Frijoles Canyon, the Indians chose the location of their homes well. The creek that runs through the canyon flows all year. On the canyon floor and mesa top there was land suitable to the cultivation of crops. And the canyon walls of soft tuff (consolidated volcanic ash) could easily be hollowed out by the Indians with their harder stone tools in fashioning storage rooms behind dwellings built against the cliff.

Cliff ruins, or talus villages, extend along the base of the northern wall of the canyon for about two miles. Other ruins are located on the floor of the canyon. The houses of stone masonry were irregularly terraced, from one to three stories in height. Some hollowed recesses at the base of the cliff also were used for dwelling rooms.

Like the other pueblo dwellers, the Frijoles inhabitants were farmers, raising the usual corn, beans, and squash. They used cotton cloth, which has been found in the ruins and which suggests that they had the loom. Since the growing season in the high Frijoles country is short, they probably obtained their cotton by trade with Indians who lived farther south. They made pottery decorated with glaze paint.

For a few centuries, the Indian farmers lived in the canyons, built villages, honeycombed the cliffs with artificial caves, and tilled the soil. But with the passing years, drought, soil-eroding floods, soil depletion, famine, and possibly disease—singly or in combination—forced the canyon dwellers again to seek new homes. Descendants of these Indians still live in nearby modern pueblos along the Rio Grande.

About ninety per cent of Bandelier National Monument is, and will remain, a wilderness. The rugged and scenic back country is accessible by about sixty miles of maintained trails, leading to such features as Alamo Canyon, the Stone Lions, Painted Cave, the Pueblo ruins of San Miguel and Yapashi, and White Rock Canyon of the Rio Grande.

Valle Grande

Another area has been considered as an addition to the National Park System in New Mexico. A 1963 bill introduced in Congress would establish Valle Grande-Bandelier National Park, about forty-six miles west of Santa Fe. Valle Grande is part of the Valle Caldera, which is among the world’s largest and has been the site of extensive studies of calderas (the collapsed summits of volcanoes). Lessons learned there have been applied in recognizing and investigating calderas in other places. Bandelier National Monument, primarily of archeological significance, lies to the east of the canyon-cut rim of the caldera. As written, the bill would have incorporated the Monument in the proposed national park.

Gila Cliff Dwellings National Monument

Gila Cliff Dwellings National Monument, forty-seven miles north of Silver City and at the edge of the Gila Wilderness Area, contains a series of ruins that portray the development of the agricultural Indians who lived south of the Mogollon Mountains. Specifically, the ruins represent a branch of the generalized culture known as Mogollon. Although part of the road to the Monument was paved in 1963, the last four-mile stretch is still primitive and should not be attempted in an ordinary passenger car except during the summer and in dry weather. In spite of the difficult road, more than 23,000 people visited the Monument during 1965. The last four miles of the road have been recently paved.

The earliest ruin yet found within the Monument is a Mogollon pit house of a type that was made about 500 A.D. It is roundish and, on the east side, has a narrow ramplike entrance some two feet wide and ten feet long. The people of this period did only a little farming (corn and beans), a little hunting, and gathered much uncultivated plant food. They made a fairly good plain-brown pottery and undoubtedly were skilled in a number of crafts whose products have since disappeared. Such things as nets and snares, baskets, and wooden tools last but a short time in open sites.

Other, later, pit house types may be seen in the Monument. Pit houses were prevalent in the area until about 1000 A.D., when influences from the Anasazi (Pueblo) Indians of the northern part of the Southwest began to affect the Mogollon people.

Square houses, built above the ground, became the style; some were of masonry, some of adobe construction, and some were built of wattle (wooden rods and twigs). A new type of pottery was also introduced at about the same time: white with black designs.

The principal ruins in the Monument are the cliff dwellings, which were built during the twelfth and thirteenth centuries. They, too, reflect the northern pueblo influence. About forty rooms, remarkably well preserved, are fitted into a series of chambers, or caves, in a low cliff of Gila Conglomerate. By about the beginning of the fifteenth century, the area was abandoned by the farming Indians.

Gran Quivira National Monument

Significant chapters in the absorbing history of New Mexico were written at three sites that have been made units of the National Park System.

Gran Quivira National Monument, near the center of the state southeast of Mountainair, preserves the ruins of a frontier Spanish mission that had been built, used, and abandoned by 1675. The Monument contains twenty-one ruined house mounds of Indian pueblos and ruins of two mission churches. It was the presence of the Indians at this location, of course, that attracted the Franciscan missionaries.

The earliest Indian pueblo in the Monument was founded about 1300 A.D.; by the 1600’s, the village, with several structures, had become the largest in the region. It was conveniently located on the south side of a hill near the cultivated fields in the surrounding lowlands. Water was a problem then as now. The Indians solved this as best they could by digging shallow wells at the base of the hill, about one mile west of the pueblo.

The first known specific reference to Gran Quivira was made in 1630 by Fray Alonso de Benavides, a Franciscan missionary. He called the pueblo the “Village of the Humanas,” and referred to the church there as having been built by Father Francisco Letrado in 1629 and dedicated to San Isidro. Humanas, now misnamed “Gran Quivira,” was later administered from the mission of San Gregorio de Abo, some forty miles to the north. In 1659, Father Diego de Santander was assigned to Humanas. Construction of the mission buildings, which he rededicated to San Buenaventura, was completed by him.

The Franciscans had a pronounced influence upon the Pueblo Indians. They stimulated trade with Mexico and the pueblos farther north. They imported wine grapes and cultivated them, and they introduced domesticated sheep, goats, cattle, and horses.

Sometime between 1672 and 1675, the pueblo and mission at Humanas were abandoned because of Apache raids, drought, and crop failures. The people first moved to the Rio Grande near the present town of Socorro. A few continued to El Paso del Norte, where, in 1680, they were joined by those from Socorro, who had fled with the Spaniards from the Pueblo Revolt of that year.

El Morro National Monument

El Morro National Monument, southwest of Grants near Ramah, was established to preserve the famous Inscription Rock, register of Indians, Spaniards, and westward-moving pioneers. About 22,000 people now visit the Monument each year.

El Morro, or Inscription Rock, is a massive mesa point of sandstone. Rising some 200 feet above the valley floor, it forms a striking landmark. From its summit, rain and melted snow drain into a natural basin at the foot of the cliff, creating a constant and dependable supply of water in a region where water is scarce. The route from Acoma to the Zuni pueblos led directly past the mesa. It was a regular camping place for Spanish _conquistadores_ and, later, for travelers from the east.

On the top of El Morro lie ruins of Indian pueblos, abandoned long before the coming of the Spaniards. And carved in the sandstone are numerous petroglyphs left by these ancient people, ancestors of the modern Zunis. Perhaps it was the petroglyphs that prompted later travelers to record their names and thoughts on the rock.

The first known historical mention of El Morro is found in the journal of Diego Pérez de Luxán, chronicler of the Espejo Expedition of 1583. Luxán stopped there for water on March 11 of that year.