Petroglyphs and Pictographs
Throughout the American Southwest indigenous peoples have left behind many clues of their existence including oral histories, ceramics, projectile points, platform mounds, canal systems and most mysteriously rock art.
Who?: The Hohokam
The Mountains of the Salt River Valley contain many fine examples of rock art. This rock art was created by the Hohokam people and other indigenous tribes of the Sonoran Desert. Incredibly, More than 550 major rock art sites have been recorded in the Sonoran Desert thus far (Bostwick 19). The term "Hohokam," is Pima in origination and refers to the ancestors of native peoples that have inhabited the Salt River valley since 300 BC. The Hohokam were agriculturalist who created amazing adobe structures, built vast canal systems, and created these intricate rock art designs. See more on Hohokam history.
In South Mountain Park Preserve the indigenous people, or Hohokam, created both pictographs and petroglyphs. Pictographs are created by using pigments to paint images onto the surface of rock faces. These pigments could have been made from plant materials, minerals, charcoal or blood. Pictographs usually take on the same style and image as petroglyphs, but are very scarce and hard to find because of wear by natural elements.
The most common form of rock art found in South Mountain Park Preserve are petroglyphs; Petro meaning "rock" and glyph meaning "carving" or "drawing" in Greek. Petroglyphs are created by using a hammer stone and chisel to peck away the outer surface, or patina, from rocks and boulders. This is referred to as the "percussion" method. This exposes a lighter colored surface of mineral below, allowing designs and images to appear on the rocks surface. In addition to the "percussion" method, "Abrading" was also used by indigenous people to slowly scratch away the rocks surface using a stone; leaving a much smoother texture behind.
Desert Varnish: (Patina)
Since the rocks patina or "desert varnish" can take thousands of years to form on the rocks surface, some petroglyphs can be seen until a new patina forms. Rock varnish is created when floating pieces of mineral matter, such as iron oxide, rest on the rocks surface and are cemented in place by bacterial secretions; leaving a dark varnish. It is thought that many of the petroglyphs found in South Mountain are almost 1,000 years old and some date back as far as 300AD! In time, most of the petroglyphs will turn as dark as the surrounding rocks surface and disappear forever!
Petroglyphs take on many different forms including: zoomorphic (animal), anamorphic (human) and geometric designs (textile). Many of the zoomorphic forms seen in South Mountain park preserve include: birds, coyotes, dogs, snakes, Gila monsters, chuckwallas, and deer. Some of the Geometric forms include: spirals, crosses, pipettes, and circles. The anamorphic motifs usually involve the figures dancing, hunting, or flute playing.
There are many theories about the meaning of these incredible etchings. Some theorize that they were used as mnemonic devices to remember significant dates, events, and oral histories of the tribe. Others believe that these mysterious marks could have been used to mark trail routes, water sources, culturally significant cites, and territorial claims. While other experts believe that these amazing and time consuming etchings could have held ceremonial or religious significance.
While some disagree on the purpose of these petroglyphs most feel that they would have been created as part of a ceremony or vision quest involving the tribal shaman and would have been of great importance considering the tremendous effort needed to create such works. Regardless, these amazing images have been left for us as gifts and clues to enjoy and ponder. Petroglyphs serve as a portal back in time and help to solve the mystery, and bridge the gap between the indigenous peoples of the Salt River Valley and our culture today.
We are just beginning to scratch the surface of the rock art mystery. A tremendous amount of continued research and archeology is necessary to keep peeling away the layers and gain a further understanding of these amazing features. Please help us protect these significant sites from vandalism.
* Attention: It is illegal to collect or vandalize petroglyph sites! Please inform law enforcement if you become aware of such activities.*
Arizona Cave Protection Law
13-3702. Defacing or damaging petroglyphs, pictographs, caves or caverns; classification
(1) Breaks, breaks off, cracks, carves upon, writes or otherwise marks upon or in any manner destroys, mutilates, injures, defaces, removes, displaces, mars or harms petroglyphs, pictographs or any natural material found in any cave or cavern; or
(3) Disturbs or alters the natural condition of such petroglyph, pictograph, cave or cavern or takes into a cave or cavern any aerosol or other type of container containing paints, dyes or other coloring agents; or
Defacing or damaging petroglyphs, pictographs, caves or caverns is a class 2 misdemeanor. (A Class 2 Misdemeanor has a fine of up to $ 750.00.)
- Andrews, John P., and Todd W. Bostwick. Desert Farmers at the Rivers Edge: The Hohokam and Pueblo Grande. Phoenix: City of Phoenix Park, Recreation, and Library Department, 2000.
- Arizona Cave Survey. 2006. 4 January 2008 <http://www.arizonacaves.org/cavelaw.htm>
- Bostwick, Todd W, and Peter Krocek. Landscape of the Spirits: Hohokam Rock Art at South Mountain Park. Tucson: The University of Arizona Press, 2002.
- Welsh, Elizabeth C. Easy Field Guide to Southwestern Petroglyphs. Phoenix: American Traveler Press, 1995.\
The Hohokam (pronounced ho-ho-KHAM) were sedentary desert dwellers who farmed the Gila River and Salt River Valleys from the time period A.D. 1-1450. Hohokam is a Akimel O’odham or Pima word which means “those who have gone” or “all used up”. The Hohokam had a complex society and lived in thriving villages in south central Arizona and northern Mexico. They traded goods with other cultures, were hunters and gatherers, built canals and irrigated farmlands and had impressive cultural accomplishments in architecture, rock art and crafts.
It is not specifically known where the Hohokam originated from, but many archaeologists argue that the Hohokam arose from local hunting and gathering cultures who lived in the desert southwest of North America since B.C. 7000. They occupied a vast territory in the Sonoran desert including as far north as Prescott, AZ west to Yuma, AZ east to Apache Junction, AZ and south to the modern day Mexican border. Dozens of villages were built by the Hohokam in the Salt River valley or modern day Phoenix. Furthermore, more than 20,000 Hohokam inhabited the region during the classic period (A.D. 1150-1450).
The Hohokam diet consisted of plants and meats collected through farming arid land, hunting, fishing and gathering. The edible plants consisted of corn, beans and squash (the tree sisters). As well as amaranth (native flour), gourds, tobacco, cotton, agave, devils claw, little barley grass and harvested wild plants. Furthermore, the meat the Hohokam ate included rabbit, deer, fish and desert tortoise.
Canals and Irrigation
The Hohokam used an extensive network of hand dug canals to deliver water to irrigate desert fields. Over 1,000 miles of canals were dug. The longest canal known was over 20 miles long and the largest canals were 10 feet deep by 30 feet wide. Two different types of canals were built, u-shaped and v-shaped. U-shaped canals had greater width and allowed water to flow at a slower rate. V-shaped canals were smaller in width and much deeper in depth, which allowed water to flow at a much greater speed. Weirs made of tree branches and brush, were used to block off and direct water flow at designated points in the canals. Many modern day canals are located in the same place as prehistoric Hohokam canals.
Through the years, the Hohokam lived in different types of houses including pit houses, compound houses, big houses and platform mounds. Pit houses were built as early as A.D. 450 and were dug 1 foot into the ground. Made from wood and cactus ribs, then covered with mud and adobe, they maintained warmer temperatures in the winter and cooler temperatures in the summer. Pit houses were single room dwellings, activities were done outside and people slept inside. Animals were kept outside and a very small pile of hot coals were placed on the floor center to keep the room warm winter.
Compound houses were built from A.D. 1150-1450 and housed families. They were made of caliche and mud stacked blocks, with stones at the base of the walls for support. The roof was made of woody cactus ribs and mesquite or palo verde beams supported the woody roof.
Big houses were built from A.D. 1150-1450 and were similar to compound houses, but were larger, had two stories and were possibly used for ceremonies and astrology. Platform mounds built from A.D. 1150-1450, were large rectangular mounds that evolved into a style with walls built of caliche rocks and adobe mortar. Researchers have hypothesized that Hohokam platform mounds were tied to the organization and operation of the canal systems or as ceremonial temples or living space (Andrew and Bostwick 2000).
The Ball Court
The Hohokam constructed ball courts from A.D. 750-1200 and the idea likely came from culture in Meso America. A ball court was an oval or bowl shaped depression, approximately 80-115 feet in length by 50 feet wide. Berms surrounded the ball courts and the floor was covered in caliche. Games were played with round balls and covered in animal hide. Ball courts possibly represented a passageway between the upper and lower spiritual worlds or were a form of celebration, entertainment, religious/spiritual activity or used as a trade site.
The Hohokam traded for goods such as raw materials and finished products by using their cotton, surplus crops and jewelry. There trade network reached from Mexico to Utah and from the Pacific coast to New Mexico and into the Great Plains. It is also likely that the Hohokam had far reaching trade routes with ancient Meso American cultures to the south. Meso America is an ancient culture area between Mexico and Honduras, where pre-Columbian societies flourished.
Red-on-buff bowl (courtesy of Pueblo Grande Museum)
Ceramics and Pottery
The Hohokam produced three types of ceramics including: plain ware, red ware and red-on-buff pottery. They made bowls, jars, pitchers, spindle whorl, effigies and figurines made from clay, sand, crushed rock and water. A paddle and anvil manufacturing technique and coil method was used to make products. Designs on ceramics include: geomorphic, zoomorphic (animal) and anthropomorphic (human) images. Zoomorphic designs include: dogs (the only domesticated animal kept by the Hohokam), sheep, deer, birds, snakes and lizards. Other images portrayed on pottery include: water, sun, wind, farming and mountains. Pottery was pit fired using wood or dung as fuel and it showed a buff color when finished. Other products that the Hohokam produced with skill include: textiles (clothing), basketry and jewelry made from shell, stone and bones.
Tools and Instruments
The Hohokam did not fashion metal tools, so they relied mostly on stone materials to make tools. Early Hohokam tools were some of the most beautiful ever made in the southwest. Tools made include: projectile points (arrowheads), knives, scrapers, drills, axes, mortars, pestles, clubs, hoes, hammers, manos, metates and musical instruments. The Hohokam made some limited types of tools from wood (digging paddles) and bone (flutes and whistles).
Rock Art: Pictographs & Petroglyphs
The Hohokam left ancient images placed on stone called rock art. Hohokam rock art consists mostly of petroglyphs, which are made by pecking or scratching at the surface of rock creating an image or design by exposing the lighter-colored rock underneath. Occasionally the Hohokam painted designs on rocks, which are called pictographs (Bostwick 1998).
South Mountain Park / Preserve located in south Phoenix, AZ is home to a couple thousand Hohokam petroglyphs. The Hohokam placed these petroglyphs on rock outcroppings and rock formations of importance to them. Furthermore, the top four rock art designs found in South Mountain Park / Preserve are: anthropomorphs, various circles, quadrupeds and snakes (Bostwick 2002).
Between A.D. 1355-1450 the Hohokam abandoned large centralized settlements and water systems. Small groups of people moved into the desert and those that stayed behind in the Gila and Salt River valleys were in smaller villages. Then in A.D. 1450 the Hohokam culture vanishes from the Sonoran desert, leaving behind remnants and artifacts of a once great society. Some possible reasons for the collapse of the Hohokam culture are: soil salinization, disease, floods, droughts, climate change, warfare and internal strife. When Spanish explorers arrived in the southwest in A.D. 1539, they encountered Piman-speaking people the Akimel O’odham. The Akimel O’odham (Pima) natives claim to be the descendants of the Hohokam.
A.D. 1 Hohokam culture begins
A.D. 50 Irrigation canals built
A.D. 500 Use of bow and arrow and atlatl
A.D. 750 Ball courts built and trade networking increased
A.D. 1000 Red-on-buff pottery production increased
A.D. 1450 Hohokam society vanishes
A.D. 1539 Spanish explorers arrive
A.D. 1-750 Pioneer Period – Small villages and simple farms, pottery begins.
A.D. 750-900 Colonial Period – Villages grew larger and first ball courts appear.
A.D. 900-1150 Sedentary Period – Further population growth, structures grew larger.
A.D. 1150-1450 Classic Period – A time of more growth and change, small groups move
to desert and Hohokam culture vanishes.
Andrew, John P. and Bostwick, Todd W. Desert Farmers at the Rivers Edge The Hohokam and Pueblo Grande. Phoenix: City of Phoenix, 2000.
Bostwick, Todd W. Landscape of the Spirits: Hohokam Rock Art at South Mountain Park. Tucson: University of Arizona Press, 2002.
Bostwick, Todd W. Pueblo Grande Museum, Profiles No. 18, Hohokam Rock Art: Ancient Images Left in Stone. Phoenix: Pueblo Grande Museum, 1998.
Bostwick, Todd W. Pueblo Grande Museum, Profiles No. 14, Pueblo Grande National Historic Landmark. Phoenix: Pueblo Grande Museum, 1994.
Hohokam Indian Page. 1998. 7 Dec. 1998 <http://carbon.cudenver.edu/stc-link/Hohokam/Hohokam.html
Olson, Justin. The Hohokam Legacy. Phoenix: City of Phoenix Parks and Recreation Department, 2007.
Pueblo Grande Museum and Archaeological Park. 2007. 1 Nov. 2007 Visit the Pueblo Grande Museum
Wikipedia. 2007. 6 Nov. 2007 <http://en.wikipedia.org/wiki/Hohokam
Information compiled by: Tony Dobbs City of Phoenix Park Ranger II, December 2007