(October 10, 2018)—Every year as the fall temperatures slowly drop—100, 90, 80, 70 degrees Fahrenheit—I get the irresistible urge to spend at least one weekend day in Catalina State Park. It is a wonderland of archaeology that I have immersed myself in since the 1980s. Usually I hold out until the temperatures are in the 70s. But this year I got a nudge from an insidious invasive species—buffelgrass. I ventured out while temperatures were still over 80. Obviously, I survived…
Introduced from Africa in the 1930s as forage for livestock and to control erosion, buffelgrass has since proliferated widely. It is fire tolerant, and when it burns it generates a high-intensity heat that can kill saguaros—the iconic plant of the Sonoran Desert.
The spread of buffelgrass has been dramatic since the 1990s, and experts have gradually developed a response for dealing with this invader. Although it may well be too little, too late in this era of incessant warming, volunteer eradicators are investing great effort in various priority places to curtail what may be inevitable.
Because Catalina State Park is without question one of my personal priority places, when Patty Estes asked for my help in assessing potential threats to archaeological resources that buffelgrass curtailment efforts might cause, it was easy for me to sign on to the cause. Patty has organized a group of volunteers for several years. The land at Catalina State Park is federal public land under U.S. Forest Service jurisdiction, with park management by Arizona State Parks. The Forest Service wants to ensure that the battle against buffelgrass doesn’t harm other important resources—in this case, archaeology—in this wonderful park.
So, because of a threatening, invasive plant, this past Saturday I had a wonderful 8-hour day checking out the archaeology of 17 acres of land within the park where the volunteers want to “get going.”
At 8:30 on Saturday morning, I was parked, applying sunscreen, readying my pack, and checking to make sure I had everything I needed. The park looked green, and there was a cool wind from the southwest. Let the hike to my study area begin.
It was about a mile-and-a-quarter to the beginning of the study area. That went quickly—my excitement at returning to this special place and the cool morning ensured that. Arriving at the first corner of my assigned acreage, I began to fully appreciate the terrain. Though this was along a major trail, I had never walked it. My previous targets were always focused on expectations of interesting archaeology. But today the target was a dreaded plant growing on steep, rocky slopes.
I have always found working alone in Catalina State Park extremely satisfying. I work with and problem-solve with people at least five days a week, so being able to roam this wonderful park and engage in the details of its archaeology all alone is my mental health investment. But there is another 70 only a few months away—my 70th birthday. Although I ignore as many of the implications of that reality as I can, I actually do try to take a bit more care on steep slopes, rocky terrain, and other potential hazards, especially when I’m alone. I’m really not as young as I used to be…
Mindful of this, I quickly devised a rational approach to this archaeological survey that I had committed to. I have seen enough of this park to be confident that level ground was an important factor when past people decided where to spend significant time—whether living, walking, or farming. So, I chose to space my survey transects on the level(ish) upper portions of the target area at 10-to-15 meters apart. Then I would run some long transects across the steep area where most of the buffelgrass is located in order to get an idea of what might be present there.
From my previous experience, even the flat portions of the landscape seemed like low-probability areas. Far from water and with no obvious wild resource densities, I didn’t expect much. Fortunately, I was wrong. Or at least, there was a bit more than I expected.
In one of my survey passes in the level zone, I saw a small pottery sherd. As one surveys, that’s all it takes to cause a change of approach. I put down my pack and pulled out my bright orange flagging tape. I walked slowly outward from this first trace of the past. When I spotted additional sherds, I placed them on a little swatch of flagging tape. I picked up each sherd and gave it a close look. One after another displayed a very distinct temper that was added to the clay by an ancient potter. Big chunks of a crushed rock called phyllite were evident. And then at the western end of this little scatter, there were four sherds that had a much finer sand temper that was clearly different. I could find no other types of artifacts. Two different vessels—or at least portions of two vessels—had somehow been broken and left behind at this place. Unfortunately, it could have been anytime from about AD 450 to 1450.
I was having a good time. No administrative duties. I had my cell phone, but I certainly didn’t plan to answer it—unless it was my wife. Life was good.
My systematic walking continued. One of the things about Catalina State Park that I find very interesting is the story of past ranching on this landscape. I haven’t had time to carry out the historic research, but I do try to record any evidence of the ranching era that preceded the park, which was opened to the public in 1983. Saturday, I kept coming across old fence posts that were often just a foot or so high, but still upright. I recorded each with a locational measurement and a photo. Old barbed wire is often left rusting in rolls that were created as early park employees opened up the landscape. And I found an enigmatic chunk of flat metal from an old soldered container. History is out there on the landscape, and a close walk-over reveals many unexpected items to the careful observer.
The first site of the day—described above—was only 3 meters wide by 6 meters long. Pretty small. After six more transects on the level land, I spotted another pottery sherd, and quickly three more nearby. Off came my pack and out came my flagging tape. This time there was more pottery. It was more widely dispersed, and there were some painted items that revealed the time that ancient peoples were here. Once again, however, there was little diversity in the types of artifacts present. I finally found one piece of flaked stone—not a formal tool, just a simple flake. The two best preserved pieces of painted pottery indicate that this activity dates between 1300 and 1450. And the one sherd illustrated here may be an indicator of activity at the late end of that time period.
Fortunately, these small, but still interesting, archaeological sites are not in areas where buffelgrass is currently growing. So, they are not a factor that could constrain the eradication efforts.
After my “archaeo-fun” of finding and recording two very small sites, it was time to walk the slopes. My three transects of those more extensive areas yielded very little. One isolated flake, two isolated pottery sherds, and nothing more. The highpoints of my travel through this zone: two deer bounded through in the early morning hours and I encountered a young desert tortoise on my final transect of the day. She was adorable—even though she peed on me when I picked her up. After I took her photo, I placed her back on the ground. Quickly, she took cover under some native grasses.
My archaeological discoveries are not earthshaking. But they do add to our accumulating knowledge about the park. My personal realization of the magnitude of the buffelgrass invasion of this special place is something that I am still processing. It grows in very dense patches. When it burns, it burns very hot, and it is feared that such fires will end up killing saguaros, other native plants, and potentially desert tortoises and other desert animals unable to flee.
This is the first in a series of blogs on public lands that I plan to write over the next year, as well as my personal sharing of a place that is very special to me. Subsequent posts will address the history of our public lands, highlighting why they are national treasures and why they are threatened.
My consistent advice to readers—get outside and experience these places.
Good information sources about buffelgrass:
Arizona Sonora Desert Museum: https://www.desertmuseum.org/buffelgrass/
Saguaro National Park: https://www.nps.gov/sagu/learn/nature/buffelgrass.htm