Natural World

Common Trees and Shrubs

Petroglyph National Monument sits on the northern edge of the Chihuahuan Desert. The Chihuahuan Desert is primarily situated in the southern half of New Mexico, West Texas and Mexico. However, there is one thin finger of Chihuahuan Desert which extends as far north as Albuquerque. The area around Albuquerque could better be described as a transitional desert grassland. Classification of deserts relies on plant and animal assemblages as well as climatic conditions. The desert around Albuquerque contains mostly Chihuahuan Desert vegetation and animals.

Nature & Science

Natural Resources

Petroglyph National Monument has much more to offer than the cultural resources for which it is so well known. Various types of wildlife utilize this narrow corridor, some in transit during migration, others for their entire lifespan. Plants, birds, insects, animals, all are part of the ecosystem that Petroglyph holds in this tiny strip of land and all will eventually encounter the millipedes of Petroglyph NM.

Another inhabitant of this area is the Rattlesnake. The park houses several varieties, please be careful when you are visiting their home. Follow this link for some guidelines about dealing with our legless friend the snake.

The remnants of volcanoe's, that produced the basalt that became the canvas for people for thousands of years, stand starkly against the western horizon and are landmarks seen from much of Albuquerque. A moderate hike will take you partway up some of these volcanic cores. For those up to a more strenuous hike, you can reach the top of some. Be sure to stay on the trails. It takes decades for this fragile landscape to recover from even incidental damage.

While hiking in the Monument, you will notice a wide range of desert plants.

As in all National Park and Monuments, it is prohibited to collect ANYTHING. Please leave all plants and flowers, rocks, artifacts and etc. for all our visitors to enjoy.

Chile Ristras, tradition, beauty and utility.

Chile Ristras of New Mexico

Ristras are the strings of chile you see hanging along fences, on patios and on portals all over New Mexico. In the Fall, you can buy ristras at farmer's markets and roadside stands. Ristras are sometimes used for decoration, and are said to bring good health and good luck. More often, they are hung up to dry for later cooking and eating.

What is a Chile?

Chiles are in the genus Capsicum, and the Solanaceae or nightshade family, which includes other New World plants, such as the tomato, potato, eggplant, tobacco and the petunia. While we sometimes refer to chiles as "peppers," they are not related to Piper nigrum, the source of black pepper.

Chiles range from the sweet bell pepper to the fiery hot habenero. They are considered a vegetable when green, and a spice when dried. Botanically, Chile fruits are considered berries.

The word "Chile" is a variation of "chil" derived from the Nahuatl (Aztec) dialect. The "e" ending is the correct Hispanic spelling of the word. English speakers have changed the "e" to an "i" and made the word refer most often to the state dish of Texas, a combination of meat, beans, and Chile pepper, called "chili."

Where did chiles originate?

Originally, Chile was found only in the Americas where it has been domesticated for 7,000 years. The wild ancestral form probably originated in the area of Bolivia and Peru. When Columbus landed in the New World, while searching for a shorter route to the East Indies and its prized spices, he found a variety of small red Chile which was similar in pungency to the black pepper with which he was familiar. He called this variety "red pepper" and took it home to Europe.

Prehistorically, distribution of Capsicum extended from the southernmost border of the United States to the temperate area of South America. Spanish explorers in the late 1500s reported that the Pueblo Indians of New Mexico were growing a mild variant form of Chile. Chile is often considered an annual, however, in suitable climates it becomes a small perennial shrub that can live for a decade or more.

Since the introduction of Chile to Europe by Columbus, it has spread rapidly along the spice trade routes to Africa and Asia, where it has become a major crop. Today, a quarter of the population of the world eats hot Chile everyday.

Why does New Mexico grow so much Chile?

New Mexicans consume more Chile per capita than any other group in the United States. It is an essential ingredient of "Mexican or Southwestern food," the fastest growing food sector in the United States.

New Mexico has an optimum climate for growing pungent Chile with low annual precipitation, irrigation is essential and increases pungency. Too much water, however, can encourage diseases and the fruit will be less pungent. The high desert climate provides a high intensity of sunlight, warm days, cool nights and daily breezes, which help to dry the plants after a rain or morning dew. Several hundred varieties of chiles are grown in New Mexico, including New Mexican (green and red), cayenne, and jalapeño.

Why is Chile hot?

It is believed that the Chile evolved pungency to discourage mammals from eating the fruits because their digestive systems destroy the seeds, preventing the spread of the plant. Birds, the natural agents of dispersal of chiles, do not feel the heat, and thus disseminate the seeds.

Chile seeds are not the source of the pungency. The "heat" is produced by alkaloid compounds call capsaicinoids, which are located in glands along the fruit's inner wall, or placenta. If you cut the fruit open you can tell how hot a Chile will be. If the placenta is a bright orange, the fruit will be hot. If the color is very pale, the fruit will be on the mild side.

The pungency is affected by the genetic makeup of the variety, the weather, growing conditions, and age of the fruit. Plant breeders can select for desired ranges of pungency, but any stress to the plant such as a few hot days or less precipitation, can increase the capsaicinoid content and cause the pungency to increase.

Chile spiciness is measured in terms of Scoville Heat Units. Heat is felt as a result of the irritation of the pain and temperature receptors in the mouth, nose, and stomach by the capsaicinoids. The physical reactions of vasodilatation, sweating and flushing, result , and the brain causes the release of endorphins which give the body a sense of pleasure. This can cause people to become "addicted" to chiles.

How do you extinguish the fire once you have eaten a hot Chile?

Some claim that plain water is best, while others claim that sugar, beer, bread, citrus fruits, tomato juice and oil can also help. Scientific research says that milk or milk based products which contain casein are the most helpful. Casein is a protein that unbinds the capsaicin from the nerve receptors on the taste buds, and puts out the fire!

What is the difference between red and greed Chile fruit?

Red and green fruit represent two developmental stages of the same Chile fruit. The plant produces green fruit, which turns red if the pods are left on the plant. The red fruit is usually dried and ground into Chile powder. Green Chile is roasted and peeled for fresh consumption, canning or freezing.

Chiles are an important source of vitamins and many essential nutrients. A green Chile pod can contain six times as much vitamin C as a Florida orange. The content diminishes about 30% with cooking and is almost completely absent in dried Chile As pods turn red, the vitamin A content increases until they contain twice the vitamin A of a carrot. Chile pods also contain high concentrations of vitamins E, P (bioflavonoids), B1 (thiamin) B2 (riboflavin) and B3 (niacin).

How is Chile used today?

Chile is eaten today as a fresh vegetable or in its dried form as a spice. It is often used in combination with tomatoes in salsas, and hot sauces, but it can also be found in many ethnic foods, meats, salad dressings, dairy products, beverages, candies, baked goods, snack foods, breading and batters. Paprika (the Hungarian words for Chile), is used as coloring in sausages, cheeses, drugs and cosmetics. Cayenne (named for a city in French Guiana) is used in hot sauce, and jalapeños (named for Jalapa, Mexico), are preserved by canning or pickling. Chiles have antimicrobial effects, and help to retard food spoilage, and important benefit in warm climates.

Today, chiles are widely used as a natural remedy. Pharmaceutical companies use the capsaicin as a topical agent in creams and liniments for sore muscles or for chronic pain as with shingles, rheumatoid arthritis and osteoarthritis.

Capsaicin is the active ingredient in anti-mugger aerosols used by many police departments.

Ornamental chiles (which are edible) are grown in colors of the rainbow by many nursery greenhouses.

Red Chile, when fed to pink flamingos, improves their feather color.

What are the methods of drying Chile?

Traditionally, Chile was sun-dried, the fruits being spread on roofs or on the ground. However, because of contamination by birds and rodents, people began to tie them together in strings or ristras and hang them on a wall. Commercial processors now use controlled artificial drying.

So, what do I do with those dried red Chile pods?

To make Chile sauce, select 12 to 14 large pods to make one pint. Pick those without any mold, disease, insect infestation, or decay, and be sure that they have not been sprayed with a plastic or shellac for decorative purposes. Remove stems, seeds, and yellow veins from the pods (leave the veins if you want a sauce which is more pungent). Wash the pods in warm water, changing the water several times.

Place the washed pods in a warm water for 30 minutes to one hour to rehydrate them. Add water as needed. Then, simmer for 10 minutes. The pulp will become soft and thick and separate from the skin. Place the pods and some water in a blender and blend until smooth puree is obtained. Run the puree through a colander or sieve to remove bits of peeling.

In a sauce pan mix one cup of the Chile puree, one cup of water, one minced garlic clove (optional), ½ teaspoon salt, two tablespoons vegetable oil, and simmer for ten minutes. Add ½ teaspoon crushed oregano leaves (optional) and simmer another five to seven minutes.

Store leftover puree in freezer.

What is the official state question for New Mexico?

Answer: Red or Green?

Common Plants

Prickly Pear Opuntia phaeacantha

The edible fruits of this plant are called "tunas" and were one of the few sweets the native peoples enjoyed before the arrival of Europeans.

Purple Aster Machaeranthera spp.

These flowers are found widespread in New Mexico during the fall. A concoction of leaves and stems was used by native peoples as a stimulant, especially effective for women in labor. Tea from the ground plant was used to treat upset stomachs.

Fourwing Saltbush Atriplex canescens

Native peoples ground and cooked the seeds of this plant as a cereal; the leaves were dried and mixed with other ingredients for flour. Ashes of burned saltbush were used as a leavening for breads.

Broom Dalea Psorothamnus scoparius

This tall shrub (sometimes called Purple Sage) has many branches, and is characterized by leaves with only one leaflet, and intense purple flowers.

Cane Cholla Opuntia imbricata

Cholla buds are high in calcium. Local native peoples ate the fruit raw, stewed or dried and ground into flour. The woody skeleton has been used for walking sticks or tied together to make fences.

Jimsonweed Datura meteloides

This highly poisonous perennial plant has a history of ceremonial use by native peoples of the southwest.

Sand Sage Artemisia filifolia

This aromatic plant has many medicinal uses. Boiled in water, the steam can be inhaled as a decongestant; as a tea it is believed to cure stomach disorders.

Scorpion Weed Phacelia integrifolia

This plant has been used medicinally by local native peoples. The powdered root or leaves are mixed with water and rubbed on sprains, swellings and rashes.

Spectacle Pod Dimorphocarpa wislizenii

This herb is a member of the mustard family. The fruit of the plant is flat and resembles a pair of spectacles.

Snakeweed Gutierrezia sarothrae

This medicinal plant is used in a variety of ways by local native peoples. Used in poultices and as a tea it is said to be useful in treating rheumatism, rattlesnake bites, eye problems, bruises, aching muscles, colds and sore throats.

Curly Dock Rumex hymenosepalus

This plant is sometimes known as Wild Rhubarb. The stems and leaves are high in vitamins A and C. Local native peoples boiled and served the leaves much like spinach and cooked the stems like young rhubarb.

Globemallow Sphaeralcea angustifolia

Remnants of this plant have been found in many archeological sites in the Southwest. It was used in several ways including, chewing the stem like gum, a cure for dysentery, and smoked as a replacement for tobacco.

Millipedes

Petroglyph National Monument is home to two resident species of millipedes, the Desert Millipede (Orthoporus ornatus) and the Slate Millipede (Comanchelus chihuanus). They are very easy to tell apart. The Desert Millipede is dark brown, averages 6 inches in length, and is the most common species seen. The Slate Millipede is dark gray, averages 3 inches in length and is considered rare. Despite their unusual appearance, they are quite harmless and extremely beneficial to the desert environment. Millipedes are nature's recyclers. They eat just about anything that is dead — plant or animal. This may sound kind of gross, but this turns out to be a very important part of the desert ecology. The desert environment is so dry that anything left out in the open tends to be preserved (this is one reason why there are so many ruins and archeological sites in the southwest). If the millipedes did not eat the dead plants and animals, they would take so long to decompose that the ground would be littered with them.

Even though the millipedes are harmless, they do have a defense mechanism. Whenever they are handled or bothered, they curl up into a spiral and ooze liquid through glands at the top of their legs. The liquid not only smells and tastes bad, but also is toxic to anything that might eat it. Millipedes are gentle creatures, but they should not be picked up. When you visit, please take the time to look at the millipedes while they go about their lives in the monument and see them for what they are—beneficial, useful and interesting parts of our environment.

Common Mammals

Mammals can be found throughout the world in all kinds of habitats, even deserts. The mammals which live in the desert are uniquely adapted to survive intense heat, limited water availability, and cold. There are many different physiological adaptations (body design and function) as well as behavioral adaptations employed by mammals to survive. Most desert mammals, for example, require minimal amounts of drinking water or none at all, and most burrow into the ground to escape the heat of the summer and the cold of the winter. The mammals at Petroglyph National Monument are no exception. Since most mammals are nocturnal (come out at night), you may only see a few different kinds while visiting. The following list includes a description and some general information.

Coyote (Canis Latrans) Head and body length – about 3 feet; tail length – 11-15 inches; weight 20-50 lbs. The coyote looks like a dog with a pointed nose and a bushy tail. Fur color is usually gray or reddish gray. Legs, ears and feet are normally a rust color. The coyote holds its tail between its legs when it runs. It is usually nocturnal, but can be seen anytime during the day. It is a scavenger and will eat almost anything it can get a hold of (including dogs and cats). Coyotes den in the ground and can run up to 40 mph.

Rock Squirrel (Citellus variegates) Head and body length – 10-11 inches; tail length – 7-10 inches. Usually seen around or on top of boulders, its coloration is a mottled gray or brown with a slight amount of rust mixed in. Its tail is long and bushy. The rock squirrel is a good climber. Its diet consists of seeds, fruits, nuts, eggs, and bits of meat. The squirrel will store food in dens underneath boulders.

Spotted Ground Squirrel (Citellus spilosoma) Head and body length – 5-6 inches; tail length – 2-3 inches. The squirrel’s coloration is a grayish brown with white spots on its back. The tail is “pencil-like” (not bushy). It is active diurnally, throughout the year, feeding on green vegetation, seeds, insects, fruits and nuts. The spotted ground squirrel is often seen near roadsides running into a burrow. It prefers sandy soil.

Whitetail Antelope Squirrel (Ammospermophilus leucurus) Head and body length 5-6 inches; tail length 2-3 inches. The squirrel looks like a chipmunk, but chipmunks don’t have white under their tail. Fur color is gray with white stripe on each side of the body. The underside of the tail is white and is usually curled over the squirrel’s back. Antelope squirrels are active throughout the year and are mostly diurnal (come out during the day). They store food, eating seeds, insects, fruits, nuts and bits of meat if they find them. This squirrel does not need drinking water.

Kangaroo Rat (Dipodomys spp.) Head and body length – 4-5 inches; tail length 5-9 inches (depends on species). Coloration is brown or grayish brown with white undersides. Tail is longer than the body in all species. All kangaroo rats have fur-lined cheek pouches where they store seeds. Kangaroo rats do not require drinking water.

Deer Mouse (Peromyscus maniculatus) Head and body length – 3-4 inches; tail length 2-5 inches. Coloration is highly variable from pale gray to reddish brown. The tail is always bi-colored – while below, dark above. Very well distributed throughout the U.S., nests wherever there is shelter. Feeds on seeds, nuts, and insects. This genus has been linked with the spread of Hantavirus in the U.S.

Black-Tailed Jackrabbit (Lepus californicus) Head and body length – 17-21 inches; ear length 6-7 inches; weight 3-7 lbs. Coloration is grayish brown with black-tipped ears and a tail with a black stripe on top. Probably the most common jackrabbit in the west. Primarily nocturnal, it sits beneath clumps of vegetation during the day.

White-throated Wood Rat (Neotoma albigula) Head and body length – 7-8 inches; tail length 5-7 inches. Coloration is grayish with a white belly and feet. The tail is bi-colored – white below, dark above. This rodent feeds on cactus, seeds and fruits. The wood rat (a.k.a. packrat) constructs large middens made of scavenged materials, then “cements” them together with feces and urine. Middens are often occupied for thousands of years by different rats. The middens give scientists an idea of what past environments were like.

Desert Cottontail (Sylvilagus auduboni) Head and body length – 12-15 inches; ear length 3-4 inches; weight 1 ½ - 2 ½ lbs. Coloration is pale gray washed with yellow. The most common cottontail in the southwest, it is primarily nocturnal, but can be seen anytime of the day. Usually burrows into the ground.

Additional Sources

Burt, W.H. and R.P. Grossenheider
1980. Peterson Field Guide to the Mammals of North America. Houghton Mifflin Co. Boston, MA. 289 pp.

Cockrum, E.L. and Y. Petryszyn
1992. Mammals of the Southwestern United States and Northwestern Mexico. Treasure Chest Publications, Inc. Tucson, AZ. 192 pp.

Olin, G. and D. Thompson
1982. Mammals of the Southwestern Deserts. Southwest Parks and Monuments Associtaiton, Tucson, AZ. 99 pp.

Millipedes of Petroglyph

A Fascinating Creature

Petroglyph National Monument is unique in many ways, but one of its most striking attributes is the seventeen-mile long volcanic escarpment. In addition to having thousands of petroglyph's on the basalt boulders, the escarpment is home to many plants and animals that may not usually be found this far north in the Chihuahuan Desert. The boulders strewn across the escarpment allow moisture and heat to be concentrated. This gives plants and animals the slight edge they need to be able to survive. One such animal is the millipede. Millipedes are known to exist in many different habitats from rainforests to sub-alpine mountaintops to deserts. The millipedes that live in these diverse habitats have adaptated in order to survive the elements. Some have developed mechanisms to keep from freezing, to keep from being eaten or to keep from drying out in the heat. In whatever habitat they occupy, millipedes are fascinating creatures that have a long history and are an important member of the ecosystem.

Desert and Slate Millipedes

There are two species of millipedes at Petroglyph National Monument, the Desert Millipede (Orthoporus ornatus) and the Slate Millipede (Comanchelus chihuanus). These two species can be easily distinguished by size and color. Desert millipedes can grow to about 8 inches long and are a chocolate brown color. Slate millipedes are only about 3 inches long and are a dark gray (almost black) color.

The best time to see millipedes is during late July, August and September after rainstorms. This is the "monsoon" season in the southwest. The Chihuahuan Desert will receive up to half of its yearly precipitation during these three months. Millipedes need the extra moisture to be able to eat and process their food. Don't be surprised, however, if you see millipedes other times of the year, because as long as there is sufficient moisture and temperature, millipedes might be out and active.

What is a Millipede?

Millipedes are arthropods, not insects or bugs. An insect typically has three body segments and six legs. A millipede has many body segments and two pairs of legs per segment. If you want to know how many legs a millipede has, count the number of body segments and multiply by four.

According to fossil evidence, millipedes were one of the first organisms to walk on land. Fossilized remains of a millipede-like creature show that it was one of the largest invertebrates to ever walk on land. The creature was almost 2 meters long and 1/2 a meter wide (6 feet long and 1 1/2 feet wide) and looked very much like some modern day millipedes. Most millipedes look about the same and have similar body structure, but there are some millipedes that have hair, spines and other appendages. The body structure of most millipedes includes a calcified head for digging in soil, antenna for sensing things like food, ocelli (simple eyes) for sensing light, mandibles for chewing food, a telson for waste excretion, and secretory glands for self-defense.

Millipedes are detritivores, earth's natural recyclers. They feed on plants and animals that have died, which recycles nutrients back into the soil much faster than waiting for the plant or animal to decompose naturally. This is very important for the survival of living plants and animals because the sandy soils in Petroglyph National Monument tend to have very few nutrients. Waiting for plants and animals to decompose naturally can take years because of the dry conditions.

Millipede Petroglyph's?

Petroglyph's offer opportunities to think about how human inhabitants interacted with nature. For instance, spiral petroglyph's are commonly found in the monument. Some American Indians think they may represent a desert millipede in its coiled, defense posture while others think they may represent water. Since millipedes are most active during the rainy season, perhaps the connection is water. As you view the images, consider how they fit into the landscape and how they may have and continue to be important in American Indian culture.

Survival in the Desert

There are few ways for animals, insects and anthropods to survive in desert conditions. They can evade or avoid climatic conditions, they can find water or their bodies can adapt. Millipedes take advantage of all three of these strategies and if successful, can live up to 10 years.
During the summer and winter millipedes evade conditions by burrowing into the soil. This reduces the amount of water they loose through respiration and allows them to escape extreme temperatures.

To find water millipedes burrow into soils that are a little more moist than their surroundings, such as the base of boulders along the escarpment. Because they are surrounded by a moist environment this also reduces the amount of water they loose .

Finally, millipedes have gone through a physical adaptation. Their bodies, or exoskeletons, are covered with a waxy coating that holds moisture in and reduces water loss when they are active.

Watch your step

Millipedes are fun to watch. Keep in mind, millipedes may be harmless, but they are wild creatures and should be treated with respect. Millipedes do not bite, however, they do have natural defensive actions. If a millipede is disturbed or threatened it curls itself into a spiral. It may also secrete a liquid toxin from its secretory glands on the side of its body. This mildly toxic secretion is meant to discourage any natural predators from eating the millipede. Feel free to look at millipedes as they go about their lives, but please do not touch. Some humans may experience a mild to severe allergic reaction to the millipedes' toxic secretion.

Millipede or Centipede - Can you tell the difference?

Millipedes should not be confused with centipedes (Scolopendra Spp.). Centipedes have a brown and yellowish, flattened body with one pair of elongated legs per body segment. Do you remember how many legs per body segment a millipede has? Centipedes have one pair of longer antenna, millipedes have one pair of shorter antenna.

Centipedes bite. They have strong jaws that inject venom into their victims. A centipede bite is a very painful and unforgettable experience. The affected area will become increasingly painful, inflammed, and will secrete pus. You'll be sorry if you attempt to touch or handle this desert creature.

Geology: Designer of the Land

A Living Landscape

New Mexico is one of the most geologically active areas of the forty-eight contiguous states. On the surface volcanoes are resting while rivers carve the earth, mountain ranges are thrust skyward, and howling winds erode and deposit sand and soil. Yet hidden beneath the surface is the culprit responsible for much of New Mexico's beauty, the Rio Grande Rift. It works slowly spreading the continental crust apart while leaving evidence of its powerful presence behind. Its effects are standing tall on the western edge of Petroglyph National Monument—the Albuquerque volcanoes whose ancient flows gave birth to an extensive mesa and a jagged, boulder-strewn escarpment. Working together—the Rio Grande Rift, volcanoes, rivers, wind—along with time, these earth forming forces continue to mold New Mexico's landscape.

The Rio Grande Rift

The Rio Grande Rift runs vertically down the length of New Mexico. The rift formed when the crust of the Colorado Plateau to the west pulled away from the crust of the Great Plains to the east. As the divergence continued, a giant crack developed where the Colorado Plateau and Great Plains meet. The crust in between was stretched and thinned like soft baking dough. Large blocks of the crust dropped down into the crack. A trough was created by this cracking and down-dropping. The trough is forty miles wide in the Albuquerque area. On the east side are the Sandia Mountains and on the west side is the Rio Puerco. Petroglyph National Monument is located in the center of the rift.

Birth of a Grand River

Before the rift formed, streams flowed from west to east, emptying into the Gulf of Mexico. Early streams carried mass amounts of alluvial sediments, sand and gravel, that began filling in the rift as it formed. The sediments filling the rift are known as the Santa Fe Formation. As the rift deepened those streams started following the north-south trough of the rift. Eventually, the streams combined into a single river called the Rio Grande. The Rio Grande flows approximately four miles east of the monument.

Albuquerque's Volcanoes

The area surrounding the rift was unstable and subject to many earthquakes that formed deep cracks, called fissures. Geologists estimate that 130,000 years ago magma rose along a five-mile long fissure and reached the earth's surface. Being a non-violent fissure eruption, lava flowed eastward in a sheet-like fashion and covered the Santa Fe Formation, an accumulation of sand and gravel up to 25,000 feet thick. The lava cooled and hardened, transforming into basalt rock.

As the lava cooled, the fissure was blocked and vents were created. From these vents, cinder and lava accumulated creating the volcanic cones we see today. Three of the cones are most prominent, standing tall on the western edge of the monument. They are known locally as the Three Sisters.

The West Mesa And The Creation Of The Escarpment

Petroglyph National Monument is located in an area commonly known as the West Mesa. The West Mesa is basalt lava rock that rests on the Santa Fe Formation, the accumulation of sand and gravel that eroded from the surrounding mountains and mesas.

Due to the erosional powers of wind and water over thousands of years, the soft sediments of the Santa Fe Formation were carried away. Without any support beneath it, the heavy basalt caprock broke and collapsed over the side, creating today's West Mesa escarpment or edge. The escarpment stretches for 17-miles along Albuquerque's western landscape and is the place where American Indians and Spanish settlers chose to carve petroglyphs.

Minerals Matter

In many areas of the monument white deposits can be seen on the rocks and boulders. These mineral deposits are a calcium carbonate substance called caliche. Caliche forms as a result of the interaction of water and decaying organisms. As plants and animals decompose, they release carbon dioxide (CO2). When CO2 mixes with water, a weak acid called carbonic acid (CH2O3) forms. The weak acid is able to leach calcium out of the soil. The calcium reacts with the carbonic acid to form an watery solution of calcium carbonate (CaCO3).

The watery solution can move through the soil and deposit itself on just about any hard surface, in this case the basalt rocks and boulders. If there is nothing for the solution to deposit itself on, it can travel down through the soil and create large beds or layers of caliche called calcrete. Caliche beds are typically found three to ten feet below the surface. Wherever the white deposits are seen it is evidence the soil has been disturbed or the rocks have been moved.

The escarpment supports distinctive plant species not found in the canyons or mesa top areas of the monument. Many native plants have adapted to the mineral rich soils and are reliant upon calcium to survive and reproduce. Some plants, such as Mariola (Parthenium incanum), grow only amongst the calcium rich soils of the escarpment.

The Petroglyphs

American Indians and Spanish settlers carved their images on these basalt boulders. The nature of the rock itself is what allows the petroglyphs to be visible. The basalt is high in iron, manganese and calcium. The combination of these minerals makes the basalt a light gray color. After long exposure to oxygen and water the iron and manganese oxidize or rust. A dark shiny coating, or patina, forms on the surface of the basalt boulders. The patina is called desert varnish.

When looking at the dark basalt boulders, you are actually looking at desert varnish. American Indians discovered permanent marks could be made by using another rock to chip off the desert varnish. Many American Indians are able to claim cultural relationships to past inhabitants of this area be cause they recognize the images as having deep cultural and spiritual significance. Please respect the importance of petroglyphs to American Indians and to the descendants of original Spanish settlers.

The Volcanoes

A Sacred Landscape

At first glance this land looks barren, covered only by sparse clumps of grasses and scrawny sagebrush. Closer examination reveals much more. Volcanic cones and dark basalt rock tell us this landscape is volcanic in origin. Also visible is the variety of desert plantlife which provides shelter, food, and refuge for small animals. It is what remains unseen that has attracted people to this landscape for centuries. This land is a place of spiritual meaning for generations of Native and Hispanic people who traveled to and visited these volcanic "sisters"as a sacred place of worship

A Natural World

Known locally as the Albuquerque Volcanoes or the Three Sisters, they are a classic and rare example of a fissure eruption. In fissure eruptions magma rises along thin cracks in the Earth's crust unlike most volcanoes in which magma rises through a vertical central vent. Here the fissure is over 5 miles (8km) long. Very long cracks like these may result in a row of aligned eruption craters—all active at the same time. Such eruptions create "curtains of fire" like those that occur today at Kilauea in Hawaii Volcanoes National Park.

The Rio Grande Rift

The volcanoes are located near the middle of the Rio Grande Rift Valley. A rift valley is a zone of weakness and thinning in the Earth's crust. As the crust is pulled apart, large blocks of land drop down forming the valley. Thin cracks open deep into the Earth releasing molten lava while blocks on one or both sides of the valley rise. The Sandia Mountains, just east of Albuquerque, formed by uplift along a major fault that marks the eastern edge of the valley. The Rio Grande Rift Valley extends from southern Colorado south to El Paso, Texas. It is one of only few active rifts. Others include the East African Rift, the Rhine Graben in Germany, and the Lake Baikal Rift in Russia.

Lava Flows and Volcanic Cones

The West Mesa, an area that includes lava flows and volcanic cones, formed about 150,000 years ago as liquid lava flowed from fissures in the Earth. There were six lava flows. The first two flows traveled the farthest creating the lava-covered plateau of the West Mesa and extended east to what is now the boulder-strewn volcanic escarpment. The boulders were later used by American Indians and settlers of mixed Spanish, Mexican and Indian background to create more than 20,000 petroglyph's. As the amount of lava production decreased, later eruptions did not flow far and created the volcanic cones we see today.

Human Activity

Over the centuries the quiet yet massive presence of the volcanoes has attracted many groups of people to the area. This is a sacred landscape to all Native people. Pueblo Indians of the Rio Grande Valley regard this place as one of the last remaining undesecrated sacred sites in the area. The Pueblos believe the volcanoes and the petroglyph's pecked into the volcanic boulders provide a direct spiritual connection to both their ancestors and to the Spirit World, the place where time began.

Western Pueblos, Navajos, and Apaches believe these landforms were created by spiritual beings who lived in the ancient past. These prominent landforms were also used as landmarks that helped guide people who traveled long distances to trade or perform religious
pilgrimages.

Hispanics view the entire West Mesa and the volcanoes as an active site of religious ceremonials and as a living reminder of a cultural heritage based on powerful spiritual ties to the Earth.

We Learn From Our Past

Recent human activity in this so called "barren" landscape has been nearly as violent as the natural forces that created it. Ranching, open-pit rock quarries, military bombing, illegal dumping, and off-road vehicle use occurred prior to the volcanoes inclusion in the national monument. All of these destructive activities scarred the land. Today, we have the advantage of learning from past mistakes. Our every action causes a reaction and sometimes it is not easy to fix our mistakes. Keep this in mind while you are visiting the monument and leave the area as though you were never there.

The Trails

Several trails take you amongst the volcanoes however, not all are measured in distance nor degree of difficulty. The trails highlighted below take you as close as possible to the volcanic cones without causing further resource damage. Native Peoples believe that hiking to the top of the volcanic cones desecrates this sacred landscape. Please respect local cultural beliefs and also help protect these unique volcanoes by not hiking to their tops.

JA Volcano and the Albuquerque Overlook
Distance: One-mile round trip from parking lot to scenic overlook and back
Degree of difficulty: Easy to moderate
This main trail departs from the parking lot and heads east to a scenic view of the Rio Grande Valley, Albuquerque, and the Sandia Mountains. This trail has three shaded rest areas with benches and trash receptacles.

Black Volcano Loop
Distance: 0.8 mile round trip from scenic overlook back to JA Volcano
Degree of difficulty: Moderate
From the scenic overlook, follow trail north. At 'Y' intersection take left trail around base of Black Volcano. On the north side of Black Volcano you will come to another 'Y'. Going left will take you south toward the main trail which leads back to the parking lot. Going right will take you north toward Vulcan Volcano.

Vulcan Volcano Loop
Distance: 2 miles from Black Volcano to parking lot
Degree of difficulty: Moderately strenuous
Follow trail north of Black Volcano to the largest of the cinder cones. The trail along the eastern base of Vulcan is difficult to find but do not give up. A gradual incline up the east side of Vulcan leads to a level, mini-volcanic valley on Vulcan's north side. Continue on trail and go left (south) when you approach the 'Y' on the northwest side of Vulcan. At next 'Y' go left again for an up-close look at this well preserved cinder cone. Follow trail down, continuing south on old road which leads to the Volcanoes Day Use parking lot.

What You'll See

In terms of mineralogy, the lava rock from the volcanoes is basalt. Basalt consists of the minerals olivine, plagioclase feldspar, pyroxene and magnetite. Various textures in the volcanic rock, from smooth to rough, as well as color variations are due to the lava's mineral content, temperature, and exposure to oxygen. Red lava rock had higher iron content and exposure to oxygen than black or gray lava rock. Other volcanic features include:

Volcanic ash & cinders - small particles of dried lava that were blown high into the air then fell to the ground like a blizzard of hot, volcanic popcorn

Spatter - thin sheets and blobs of magma that cooled rapidly and coat the sides of the cones with a hard crust.

Caliche - a white, calcium carbonate substance covering buried portions of rocks.

Lichen - a complex "plant" composed of an algae and a fungus that live symbiotically on rock surfaces. Colors vary from green, yellow, orange, to rust.

For Your Safety

Dress appropriately and always wear sturdy hiking boots with ankle support. Spring, fall, and winter winds are chilling. Layer clothing and wear a hat and a windbreaker or jacket. During spring and summer months apply sunscreen generously, wear sunglasses, and a hat or

Dogs are permitted on the trails provided they are on a leash, no longer than 6 feet, at all times. Bring a bag to pick-up after your dog and dispose of it in the trash receptacle. Remember to bring plenty of water for your dog(s).

Enjoy your visit at Petroglyph National Monument.

Volcanos and Basalt

The rock that makes up the West Mesa escarpment is vesicular basalt. The basalt flow originated from fissures marked by five volcanic spatter cones that can be seen along the western horizon of Albuquerque. Located within the monument boundary, these cones are considered part of a sacred landscape by many Puebloan people today. The last volcanic eruption occurred approximately 150,000 years ago. Although the area is still geologically active, geologists consider these spatter cones to be extinct.

The basalt that makes up the boulders on which the petroglyphs are carved was originally a light gray color. Over time the surface of the rock was coated by a thin black or dark brown layer of oxidation scientists call "desert varnish." When the surface of the boulder is pecked or abraded, the lighter rock underneath is exposed, displaying a stunning light gray-on-black contrast.