Overview: Boca Negra Canyon is one of the four major visitor sites at Petroglyph National Monument where the visitor can get up close and personal with the works of art and cultural remnants of the Ancestral Puebloans that inhabited the Rio Grande River Valley where the metropolis of Albuquerque New Mexico now sprawls. The National Park Service estimates that there are between 20,000 and 25,000 petroglyphs located within the monument's boundaries. This is the single largest concentration of petroglyphs in the nation and is the only National Park Service area of jurisdiction, specifically dedicated to the preservation and display of Native American heritage, culture and art in the form of petroglyphs. Boca Negra contains just 4 percent of the petroglyphs found within the monument.
Area Geology & The Native People: Along the west side of the valley, a mesa of volcanic basalt and cinders looks down on Albuquerque. Approximately 150,000 to 200,000 years ago extensive faults in the Rio Grande rift zone located here, spewed lava at least six times over the course of about a year. The first two of these eruptions poured huge volumes of very fluid magma that flowed through and filled arroyos and flowed around hills covering 50 square miles of the sandy Santa Fe Formation that forms the valley floor. These first two eruptions were followed by progressively thicker eruptions with less and less fluid movement, to finally form the volcanic cinder peaks that that line the western edge of the mesa. Since the mesa was formed, constant erosion of the sandy underlying soil along the eastern edge of the mesa has created peninsulas of basalt that now jut eastward where the lava originally had filled an arroyo and canyons have formed where the lava had skirted ridges and higher sections of the sandy valley floor. This reversal of features is a classic example of what is called reverse topography.
The eastern edge of the mesa or the escarpment is retreating today to the west as erosion slowly pulls the sand out from under the layer of basalt and it collapses chunk by chunk to roll down to the base of the valley floor. The surface of these boulders of basalt have oxidized to a dark brown / black finish that when chipped or scratched reveals the lighter color of the volcanic rock underneath. This natural desert varnish or patina became the canvas for the people that journeyed from one of the 40 pueblos that lined the Rio Grande River nearby. They came to tend crops, hunt, celebrate religious ceremonies, practice healing rituals and record their thoughts, visions, experiences, and important subjects in their lives in the form of the petroglyphs we reverently admire today on the boulders of the escarpment.
As early as 12,000 years ago Paleo-Indians began roaming the valley floor and the west mesa, hunting and gathering food as they followed the herds and the seasons. The landscape that these early valley residents lived in would not be recognized today. Abundant rain filled many shallow lakes and lush vegetation grew everywhere. Many of the animals that we see there today were absent and those that were there were joined by many small birds and mammals as well as camels, mastodons, mammoths and bison, long extinct from the area. Gradually the rains slowed and the area became more and more arid, shifting the valleys environment to what we recognize there today.
The early inhabitants of the valley and mesa were gradually replaced by less nomadic, archaic people. Remnants of their culture have been found on the mesa and lower areas of the valley where they ground grain and other foods in well worn metates. A severe drought struck the southwest between the years of 1275 and 1300 A.D. This lack of water forced many of the tribes throughout the southwest to relocate to areas where perennial sources of water were located. The Rio Grande River valley was one such area. During this time frame the size of the pueblos grew as the people shifted away from the small family size dwellings, to adobe pueblos that contained between 100 and 800 rooms. Many of them were as high as 3 stories with a central plaza. Between the years of 1300 and about 1540, 40 of these pueblos were built along the Rio Grande between Bernalillo and Belen (40 miles) and as many as 1,000 people lived in some of these pueblos.
The Pueblo Indians that lived in the valley planted crops along the mesa in terraced plots that utilized rock diversion dams to slow and channel water to these crops. They also planted crops along the Rio Grande and used irrigation channels to pull water from the river. They continued to hunt wild game as well and life in the valley flourished. Extensive trade networks were established to as far south as Central America and west to the Pacific Ocean. Sea shells, tropical birds such as the Macaw Parrot that became important in their religious ceremonies, Turquoise and other gem stones, copper bells from Mexico, cotton linens, baskets and pottery were all traded.
In 1540 Francisco Vazquez de Coronado marched north from Mexico with his army and made contact with the pueblos. While wintering at one of the pueblos, violence erupted and the Spaniards destroyed several of the pueblos. Many of the Pueblo Indians fled the area and did not return until the Spaniards departed the area in 1542. The Indians enjoyed many more years of peaceful living in the valley until the arrival of Juan de Onate who was leading colonists from Mexico to settle the area. Much of what had been Indian land in the valley was colonized and split into land grants by the Spanish crown and more and more colonists flowed up from Mexico between 1610 and 1680. Spanish ranches or Haciendas sprang up throughout the valley and many missions were built in the Indian pueblos.
Throughout the early to mid 1600s the Pueblo Indian population in the valley fell as sickness and disease brought in by the Spanish spread in the cramped confines of the pueblos. Brutal treatment of the Indians by the Spaniards and repeated crop failures also caused the Indian population to fall. In the year 1680 the first American Revolution took place. Indians across the southwest revolted against the Spanish and drove them out of the area and south to and area near where El Paso Texas now lies. This was the first time a Major European power had been defeated and forced out of an American territory. For 12 years the Indians again enjoyed freedom. But the Spanish pushed north again and reoccupied the southwest in 1692, this time to stay. One of the Spanish land grants encompassed what is now Petroglyph National Monument. Spanish sheep herders tending flocks on the Atrisco Land Grant have also contributed many petroglyphs to the monument. They can be seen alongside the Indian petroglyphs throughout the monument. These include Christian crosses unlike the Indian's crosses encased in a box as well as what are believed to be animal brands and ornate letters.
The Glyphs: What do the petroglyphs mean? This is the eternally unanswered questioned and the likelihood of a "Rosetta Stone" being found that would give meaning to the seemingly random drawings etched upon the face of a rock is beyond remote. The message is in the eye of the beholder today and any guess as to their meaning or reason for being created is as good as the next persons guess. It could be safely assumed that many of the images pertain to religious beliefs and ceremonies as well as important items from the people's surrounding environment such as various animals and plants. Their meaning could also be a product of placement in addition to subject matter. Is the image in an upright or different orientation? What direction does it face? Is it exposed to the sun or in perpetual shadows? Is it near a spring, a cave? What other petroglyphs are nearby? Is it near the worn surface of another boulder used to grind herbs, plants and minerals for healing ceremonies? We can only guess what the glyphs creators were thinking, trying to tell their gods or were trying to convey to those who would follow.
The petroglyphs were made primarily by using a stone or two stones like a hammer and a chisel to gently peck off the patina on the boulder's surface and creating the image the artist desired to create. Images started being created like this around the year 1300 and is known as the "Rio Grande Style". This style of petroglyph etching continued to be used for about 380 years until near 1680. This timeframe coincided with the large increase in the population in the valley and the construction of the 40 nearby pueblos and the Pueblo Revolt that forced the Spanish invaders back towards Mexico.
Dating of the petroglyphs is an inexact science however some pretty close estimations can be made using information that we have available to us. In the future more accurate age estimates will evolve as our knowledge base broadens with continuing research, improvements in technology and new discoveries. Comparisons between similar designs found on dated pottery, baskets, and painted murals can be used. The reestablishment of the desert varnish over top of the petroglyph indicates and older glyph. Etchings on top of an older etching will also show relative age. In general, the glyphs located throughout the Rio Grande valley are currently estimated to be somewhere between 3,000 and 300 years old with the majority of the glyphs at the monument being between 700 and 300 years old.
Ruin & Archeological Site Etiquette: All petroglyphs and other Native American artifacts in the monument and elsewhere across the southwest are protected by federal law. Do not deface, remove, add to or in any way damage the petroglyphs or other artifacts. Do not touch the petroglyphs, as the oil from your skin will have a negative effect on the glyph and its ability to remain visible for future generations of visitors. As we have all been told again and again, take only photographs and leave only footprints. Prior to the establishment of the monument in 1990 many of the glyphs were vandalized either by hand or gunfire. Many examples of this vandalism are visible in my photo set of this area. This vandalism has forever ruined some wonderful remnants of our early Native American heritage. Please help to protect these priceless treasures of time for future generations of visitors.
Hike: This is a relatively short hike of only about a 1/4 mile in length however there are a number of excellent petroglyphs available for viewing along the trail and randomly among the basalt boulders of the escarpment. From the parking area, walk to the edge of the canyon and you will see a set of stairs to your right. Descend the stairs to the bottom of the canyon and walk about 100 yards down canyon. From the trail you will see several petroglyphs on boulders up the side of the canyon. Most of the glyphs are not visible from the trail. Reverse your direction and slowly work your way up canyon along canyon left or your right as you face up canyon watching closely for the glyphs to reveal themselves to you. Some of the glyphs are right up near the top edge of the canyon lip. Work your way to the head of the canyon and then exit near the picnic tables and return to the parking area to complete your hike.
Currently the monument does not actively restrict off trail access to the glyphs however they strongly discourage it. I estimate that about 80 percent of the glyphs can only be viewed if you walk up and down through the boulders closely looking on all sides of them. The Monument is however seeking to establish a use plan that would prohibit off trail travel to examine the glyphs. Enactment of this use plan will be double edged in that many glyphs again, are not visible from the trails and will not be available for viewing however site impact by visitors on vegetation, wildlife habitat, and the petroglyphs themselves will be greatly reduced by restricting visitors to the trails.
I have extensively photographed a large number of the glyphs, boulder to boulder throughout the monument and these photos will be posted for viewing should the glyphs become inaccessible in the near future. A set of binoculars will greatly assist you in seeing the glyph details should you choose to remain on the trail or even view them from the parking or picnic area. Current Native Americans believe that the petroglyph chooses who it will reveal itself to. It is very easy to miss them and taking your time with a slow examination of the area will give more of them the opportunity to befriend you!
Pets are currently welcome and doggie bags are provided at the trailheads for you to use to pick up after your pet. Please use them!
The trails are rough, uneven and mostly unpaved and as a result are not accessible to wheelchairs.
Cautions: Due to the rough nature of the trails and the topography in and around the petroglyphs it is very easy to slip, trip and fall. Exercise caution in maneuvering around, over, up and down the boulders scattered along the escarpment.
Check out the Triplogs.