Petroglyphs, agaves, and cacti at Agua Fria National Monument

Agua Fria National Monument is located about 40 miles north of downtown Phoenix. Established in 2000 under President Clinton, it encompasses 72,000 acres of semi-desert grassland and protects what is considered to be one of the most important system of prehistoric sites in the Southwest, spanning about 2000 years of human history.

Managed by the Bureau of Land Management (BLM), Agua Fria is completely undeveloped and offers no visitor services. Agua Fria can be accessed from Interstate 17 via three dirt roads, all of which are unmaintained after a few miles. Even in a high-clearance 4WD vehicle, navigating the roads can be challenging. Expect a rough ride that will shake loose anything that isn’t bolted or tied down.

I recently had the privilege of going to Agua Fria with Ron Parker, author of the book Chasing Centuries: The Search for Ancient Agave Cultivars Across the Desert Southwest (Sunbelt Publications, January 2019). In the early days of Ron’s explorations, he simply wanted to see Arizona agave populations in habitat. However, when he started to discover the modern-day offspring of “domesticated” agaves growing near many prehistoric ruins, his interest began to shift to what he calls “pre-Columbian cultigens.” Six of them have been formally described from Arizona: Agave delamateri, A. murpheyi, A. phillipsiana, A. sanpedroensis, A. verdensis, and A. yavapaiensis. More recently, Ron’s focus has been on documenting and photographing pre-Columbian rock art throughout Arizona.

Ron is an intrepid explorer and has a 4WD Jeep with 10-ply tires, the perfect vehicle to get to remote places over tough terrain. Our destination was on the eastern side of Agua Fria, and without his Jeep (and Ron’s off-road driving skills) we would never have made it there.

Please note that if you come to Agua Fria in a passenger car, you’re not going to see much. The best you might be able do is Pueblo La Plata, the most accessible prehistoric site in the monument. Cynics might say it has been sacrificed to satisfy the curiosity of the few thousand visitors that make it to Agua Fria every year. We didn’t stop at Pueblo La Plata on this trip so I have no photos to show, but it should be (relatively) easy for me to go there by myself at some point.

Agave aff. chrysantha

Located at an elevation of 3500 to 4000 feet, Agua Fria National Monument includes two mesas—Black and Perry Mesa— separated by the canyon of the Agua Fria River, and several smaller valleys (this BLM map shows the lay of the land). The vegetation is riparian forest along the river and rolling grasslands and juniper savannah on the mesas.

The most common agave at Agua Fria is Agave aff. chrysantha, although it’s mostly found as isolated specimens rather than dense populations. Based on Ron’s suggestion, I’m referring to it as aff.  (affinis) chrysantha, because it has a close affinity with chrysantha although it may be a hybrid or something else that hasn’t been described yet. Agave chrysantha is native to a wide swath of central Arizona and quite variable in appearance and size. Ron has found A. chrysantha specimens as large as 8 feet in the Pinal Mountains southeast of Phoenix, but the plants we saw at Agua Fria were no more than 2 feet in diameter. Much more research, especially genetic analysis, is needed to untangle the Agave chrysantha complex.

Agave aff. chrysantha

Agave aff. chrysantha with damage from running bugs (Caulotops barberi)

Agave aff. chrysantha

Agave aff. chrysantha

Agave aff. chrysantha

In terms of cacti, we encountered quite a variety, including Escobaria vivipara, Echinocereus engelmannii, Opuntia engelmannii, Opuntia phaeacantha, Cylindropuntia acanthocarpa, and Cylindropuntia whipplei:

Escobaria vivipara

Echinocereus engelmannii

Echinocereus engelmannii

Opuntia engelmannii

Opuntia engelmannii

Opuntia phaeacantha

Opuntia phaeacantha

Cylindropuntia acanthocarpa

Cylindropuntia whipplei

The agaves and cacti we encountered may not have been the most photogenic specimens of their kind, but seeing them in their natural environment is such a thrill for me. After a while, Ron started to tease me for stopping so much to take photos of plants he thought were completely ordinary. Except to me, even an ordinary agave or cactus in habitat is extraordinary.

Ron walking across the rock-strewn grassland on Perry Mesa

Our destination was a remote site on Perry Mesa that had once been home to a poorly understood group of people now known as the “Perry Mesa Tradition.” Archeologists still don’t know the identity, origin, or ultimate destiny of the Perry Mesa people, but they lived on this windswept plateau from approximately 1250 to 1450 CE and left behind stone ruins and, even more remarkably, hundreds upon hundreds of petroglyphs.

The ruins at the complex we visited—essentially collapsed rock walls that had once formed room blocks—were very hard to photograph so I didn’t even try. Compared to elsewhere, they are not well preserved. To give you an idea of what the ruins look like, here is a photo from Ron:

Collapsed rock walls that had once formed room blocks

But there is plenty of other evidence of the Perry Mesa Tradition that is far more impressive:

In the spot you see in the photo above and the three photos below, there are dozens of hollows in the rocks. They’re easy to see in these pictures because they’re filled with water from a recent storm. These depressions are metates carved out of the bedrock. They were used to grind grains and seeds, primarily corn, by means of a handstone called a mano.

It felt decidedly odd to be standing on this vast and silent plateau, contemplating the remains of a civilization that had existed here so long ago. There was nobody else around, just Ron and me, and there were no man-made sounds, just the soft whistle of the wind.

Metate field

The site we visited is at the edge of a plateau which drops down into a fairly wide valley bounded by rolling hills beyond.

The petroglyphs we were here to see are pecked into the cliff face. In the photo above, you can see how sheer the cliff is.

Getting to the petroglyphs involves a fair amount of scrambling over rocks, trying to avoid loose boulders that might shift as well as the occasional catclaw acacia (Senegalia greggii) that seems only too eager to grab your clothing and skin. Fortunately, Ron had done this kind of climbing many times before and expertly led the way.

The most enduring legacy of the people of the Perry Mesa Tradition are the countless petroglyphs pecked into rocks and cliff faces throughout Perry Mesa. Some of the petroglyphs we saw were clustered in massive panels:

Animals, mostly deer and antelopes

Petroglyphs generally fall into three categories based on what they show: zoomorphs (animals), anthropomorphs (people), and abstract/geometric shapes.

Animals are the easiest to understand, seeing how hunting played a major role in the lives of the Perry Mesa people.

People are often depicted with broad shoulders, exaggerated hands, or giant headdresses; the latter are probably shamans.

Geometric shapes include circles (often concentric) and all manner of symbols and unidentified objects. Somewhere else in Agua Fria National Monument is a spectacular petroglyph that may depict the night sky during the Supernova of the year 1054. If that’s the case, the petroglyph would predate the Perry Mesa Tradition (1250-1450).

Antrophomorph with giant headdress

Simple concentric circles

Some petroglyphs are painted over with red pigment. It’s amazing that the color is still so vibrant after 800+ years!

Ron with a painted petroglyph

Two more painted petroglyphs. Also notice the very large (mythical) animal in the center

The most spectacular painted petroglyph is the Man on Fire

Man on Fire, likely a shamanistic figure

Now let’s scramble around on the rocks and see what we can find. Just follow Ron!

Me next to an impressive panel showing a sun (?)...

...several deer...

...and a large shaman-type figure

Connected pair of hands

More animals, typically ungulates like deer and antelopes:

Human and deer. They’re at eye level; what does it mean?

The next three photos show a shield. Is it a heraldic symbol—a coat of arms, as it were—of a particular tribe?

And finally two photos showing modern-day graffiti. This doesn’t appear to be too much of an issue at the remote site we visited, but in more accessible locations it’s a big problem.

Notice the initials E.B. on the top right of the rock

Airplane and initials

A few more cactus photos before leaving:

Opuntia engelmannii

Opuntia engelmannii

Opuntia phaeacantha

Cylindropuntia whipplei

Cylindropuntia whipplei

Cylindropuntia whipplei

Before we called it a day and headed back to Phoenix, Ron took me to a population of Agave parryi that is out of place at an elevation of below 4000 ft. While variable, Agave parryi is a montane species typically found at 4500 ft or above; on Mount Lemon northeast of Tucson, there’s an Agave parryi population at 7000 ft.

Is this population of Agave parryi simply an outlier? Or was it planted here a long time ago by the inhabitants of this mesa? Ron believes the latter is the case. He thinks Agave parryi was brought here from somewhere else and cultivated as a source of pulque, an alcoholic beverage made from the fermented sap of agaves that are close to flowering. In Central Mexico, pulque has been made for at least two thousand years.

Agave parryi

Agave parryi

Agave parryi

Agave parryi

Agave parryi

Agave parryi

If want to learn more about the Perry Mesa Tradition, this visitor guide from 1999 is a great resource. It also includes an appendix with drawings of petroglyphs found on the mesa.

If you haven’t yet read Ron Parker’s book, Chasing Centuries: The Search for Ancient Agave Cultivars Across the Desert Southwest, I highly recommend it. It’s a fascinating exploration of pre-Columbian history, archaeology, and botany, all revolving around agaves, both natural species and cultivars created by the people who once lived in Arizona’s agave country.

And if you want to visit Agua Fria National Monument yourself, here is the official BLM access map. As I mentioned at the beginning of this post, there are no services so you’re on your own. Be prepared and bring water!

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