Earth Oven: Searching for the Trifecta

by Jake Sullivan and Brooke Bonorden

Let me begin by explaining what an earth oven is. An earth oven is a cooking technology that has been widely used in the Lower Pecos for thousands of years. To create an earth oven, a pit is dug into the ground and a fire is built. Large stones are placed amongst the flames; these stones retain the fire’s heat and become the oven’s heating element long after the fire has died out. Next, a layer of packing material is laid across the hot stones in order to insulate the food from direct heat and provide moisture. Prickly pear pads work great for this and can be found in abundance in the Lower Pecos. The food load, the trimmed hearts of the desert succulents sotol and lechuguilla, is placed on top of the packing material followed by another layer of packing material. The oven is then capped by a thick layer of earth to prevent precious steam heat from escaping. After cooking for at least 36 hours the food is ready to be unearthed and consumed.


Processing sotol for an experimental earth oven.

The baking process turns the complex carbohydrates within the plants into sugar. These plants also contain a chemical called saponin, which is inedible in its raw form but is rendered harmless by the cooking process. I can tell you from experience that baked sotol doesn’t always taste good, but it is a reliable food source in a harsh and highly variable environment.

As part of the ENC project, one of the research topics we are interested in is calculating how much earth oven processing occurred at different sites, i.e. how many times each earth oven locale was used. Fire-cracked rock (FCR) is the most common remnant of an earth oven cooking facility found in an archaeological context. In the field we have been sizing, counting, and weighing the FCR that we find in each layer of our excavation units. What we find most often, and what makes up the majority of the enormous talus slopes in front of the shelters, are FCR that have been discarded after multiple heating events and are now too small to store heat efficiently. However, in order to find out how much earth oven processing has occurred we need to do more than just count and weigh the burned rock coming out of our units. We are planning to do this by trying our hand at some Experimental Archaeology.

One of the challenges for archaeologists is understanding how the things you find in the ground are related to human activity—especially when it comes to burned rocks.  So, we carry out different experimental archaeology projects to help us figure out what burned rocks in the ground might represent. Collectively, we have built many earth ovens to demonstrate the plant baking process from start to finish. However, beyond demonstrating how local edibles were processed by those who occupied the rockshelters we work in, we did not collect any real scientific data to help us answer questions related to earth oven processing.  So, we are planning a series of long-term experiments by creating our own earth ovens. We hope to document the number of plant baking episodes necessary to significantly reduce the size of our heating elements (rocks) to the size of the FCR that we are finding in burned-rock middens (BRM) throughout the canyon.

On Thursday the ENC crew searched the property surrounding the Shumla campus for a new site for our upcoming experimental earth oven. When seeking out the new oven location we tried to keep in mind the qualities that would have appealed the natives who were using this cooking technology for their survival. The vast majority of optimal locations we saw while traipsing through the always-thorny local shrubbery were already occupied by evidence of prehistoric plant baking – fire-cracked rocks. What makes a location optimal is its proximity to the trifecta: fuel, food, and dirt. Native peoples would have tried to find a location that was relatively close to all the fuel, food, and dirt they needed to construct and fill the oven so they wouldn’t have to expend extra energy hauling in supplies. Eventually we found a pristine location untainted by archaeological evidence. 

In anticipation of building our first earth ovens in the new locale, our first task is to collect phosphate samples at the recommendation of our geoarchaeologist colleague Ken Lawrence.  Phosphorous (or P) analysis looks at the phosphate that accumulates in sediment by many aspects of human activity. What’s great about phosphorous is that it decays very slowly through geologic time, so it’s a reliable element for targeted study. Our goal in using this method is to analyze how quickly and at what levels phosphate will accumulate in sediment that has been manipulated by plant processing and baking. To accomplish this we will be taking initial baseline samples at the oven location, and then Ken will come back and collect more once we have started processing.  This is important to archaeologists because it gives us another way to interpret the intensity of the plant processing that occurred at local sites. By understanding how much earth oven processing occurred, we will be able to compare how many times different sites were used, and gain a better understanding of how people moved across the LP landscape.


We can’t believe how good it tastes!

 In a few weeks we will tap the trifecta and start building ovens and monitoring the cracking rocks.  We will also be following a pattern that native peoples must have relied on – in the winter, lechuguilla and sotol are among the few potentially edible plants that can be harvested.  

Low Impact-High Resolution: Using the Strat System in Eagle Cave

By Charles Koenig

Within archaeology, and certainly in several of our blog posts, you will hear the term stratigraphy.  So, what exactly do we mean by stratigraphy?  Within any archaeological site there are different layers of stuff—artifacts, rocks, different kinds of dirt or sediment—and each of these layers may contain different things from the layers above or below it.  We consider each layer to be a stratigraphic unit, or strat for short.  In some cases these strats can be the result of human activity (e.g., making fires) or when a river floods and leaves behind a deposit of sand and clay.  All things being equal, over time strats build upward and older strats are continuously covered by younger strats.

A photograph of a layer cake borrowed from Google (right), and a hungry archaeologist's version of the same cake (right).

A photograph of a layer cake borrowed from Google (left), and a hungry archaeologist’s version of the same cake (right).

In other words, imagine a triple-decker cake as a substitute for an archaeological site.  This cake has chocolate cake on the bottom, strawberry in the middle, and white cake on the top.  Between each level of the cake are layers of frosting.  When you cut into this hypothetical cake, you will be able to see all the different layers, and to an archaeologist each layer of this cake (e.g., the chocolate, strawberry, and white cake as well as the different frosting) can be considered a unique strat.  Actually, archaeologists even refer to very distinct ideal layering within a site as “layer-cake stratigraphy” (a classic example of “layer-cake” stratigraphy from an archaeological site in the Lower Pecos is Arenosa Shelter, which you can learn more about here:

When you study the different strats within the cake, you can start determining the order in which the cake was constructed.  For example, the chocolate cake layer at the bottom is the oldest part of the cake, and then the strawberry frosting was spread on, and so on).  As you study and record how the different cake and frosting layers were placed onto the cake, you begin to understand how the complete cake was created.  Understanding how a site (or cake) formed is what archaeologists call site formation processes.

Now, to jump back to stratigraphy in Eagle Cave.  One of the tragedies about Eagle Cave is when the University of Texas wrapped up their excavations in 1963, they left all of their excavation units open (as did the Witte Museum in 1936).  Over the past 50 years all the walls have collapsed, but there are still large depressions where the units once were.  When we (Steve and Charles) began writing the research design for Eagle Cave, we knew we would be able to take advantage of the existing units to expose any intact stratigraphy.  However, we knew from previous excavations at Eagle Cave the stratigraphy is anything but layer-cake—dozens of thin, hard to see strats mixed in with thick, rocky strats all churned up by rodent burrows and human-dug pits—in short, extremely difficult stratigraphy to carefully document and understand.  So, the big challenge became: once we expose the stratigraphy, how should we document and sample the complex layering within the site while minimizing the overall impact our project has on the remaining intact deposits?

What we decided upon was to use a version of Steve’s Strat System from his work in Belize in the early 1980s, and came up with the motto, “Low Impact-High Resolution,” meaning we want to learn as much as we can while doing the least damage to the site.  To go back to our layer-cake analogy, imagine you are a food critic and you have 10 of your closest food critic friends coming to sample every layer within the cake tomorrow.  But, because the cake is so delicious you need to save enough cake for 10 more food critics to sample the cake every 50 years for the next 10,000 years (fortunately this hypothetical cake never rots).

Over the next 6 months (and likely on and off for several years) we will be documenting the stratigraphy of Eagle Cave at dozens of different spots.  All of these exposures will be in areas which have been previously excavated or dug into by critters or artifact collectors so we are only damaging small portions of the intact stratigraphy.  We are calling these Profile Sections.

Steve and Tina Exposing and Cleaning PS001 prior to strat identification and subsequent sampling

Steve and Tina Exposing and Cleaning PS001 prior to strat identification and subsequent sampling

Yesterday we documented and began to record our first profile section: PS001.  The location of PS001 was selected because there was a large animal burrow and adjacent backdirt pile, and we could just make out what appeared to be intact stratigraphy above the burrow.  The burrow angled downward into the deposits (and can be seen toward the bottom of the profile), but by cutting back only a few centimeters above the burrow we were able to expose ~60 cm tall profile section. We were very surprised to encounter intact stratigraphy only a few centimeters below the ground surface, so we are very encouraged to begin exposing and documenting additional Profile Sections.

Image of PS001 exported from ArcGIS. A 3D model of 60 photographs was used to produce the image.

Today we began documenting the different strats in PS001, but those descriptions are incomplete.  When we begin our sampling we will likely take small matrix samples out of each identified strat, and screen the material through nested geologic sieves.  We will then be able to coordinate with our collaborators (like Phil Dering and Charles Frederick, among others) to begin analyzing all the different material in each strat – sediment, plant parts, animal bones and so on.  This is where High-Resolution comes into play.  We want to systemically sample each strat individually so we can gain a more detailed understanding of when and how the site formed over time, how the site was used during different time periods, and use the data to address many other questions.

Feel free to check out the 3D PDF of PS001 at the Link below!

3D PDF of PS001

Month 1 in Review

By Brooke Bonorden

As the end of January (and our fourth week of excavations) rapidly approaches, it seems appropriate to give an update of our overall progress with the Ancient Southwest Texas Project.

When Dan Rodriguez began excavations in Skiles last June, he encountered a thick flood deposit in both of his 1 x 1 meter units.  This was very exciting because it suggested that any archaeology beneath the thick Rio Grande flood-mud could be intact and undisturbed.  So, four weeks ago we began to expand on Rodriguez’s two units to address two main research questions: 1) what is the depositional history (both natural and cultural) within Skiles Shelter and 2) how much earth oven plant processing is represented by the substantial burned rock midden talus at the site.

In order to get an idea of the depositional history of the site, we have opened five new units (bringing the total to seven units in Skiles), and have excavated multiple layers within each unit. For those unfamiliar with archaeology this may not sound terribly impressive considering we have spent almost an entire month in the field, but when taking into account all of the paperwork/photography/lab work accompanying each unit and layer we have made significant progress.  We have also produced 3D models of each unit/layer that has been excavated, deriving these images from a series of overlapping photos. These models are far more detailed than any scaled drawing of a unit or profile could ever be, so our techniques are essentially revolutionizing traditional archaeological methods. We are also transitioning from recording our progress on paper field forms to using both tablets and laptops for digital recording.

How many archaeologists does it take to supervise one crew member?

How many archaeologists does it take to supervise one crew member?

No formal analysis of the artifacts collected from these units has been conducted, so my observations of what we have learned from the site thus far are not necessarily profound, but I can tell you a couple interesting things.  The large flood deposit appears to overlay an earth oven facility (aka, burned rock midden or BRM) where indigenous peoples used earth ovens to process plants like lechuguilla and sotol.  Where we have exposed the flood deposit and the BRM layer, it appears the BRM was higher in elevation toward the drip line of the shelter, which caused the flood to deposit sediment in a thicker layer toward the back wall of the shelter.  As of this moment we have collected several diagnostic projectile points, but have only exposed the top of the BRM and have not received any radiocarbon dates, so we do not know much more about the site.

Variety of dart and arrow points recovered from Skiles Shelter.

Variety of dart and arrow points recovered from Skiles Shelter.

Skiles excavations as of 1-27-2014

Skiles excavations as of 1-27-2014

We have recently begun switching gears so to speak, and are beginning preparations for our Eagle Cave excavation. We have spent the last couple days stabilizing trails into the site to help protect it.  Tomorrow we will begin laying down rubber matting on trails inside the shelter to help keep down the dust and prevent potential damage by visitor traffic.  Last week when we did the Pole Aerial Photography of Eagle Cave and established our datums from which we will calculate our elevations, northings, and eastings (necessary for site mapping).  We are also addressing logistical issues that we anticipate arising once we break ground at the site, but I won’t go into detail about that.

Crew building trails in Eagle Cave.

Crew building trails in Eagle Cave.

In addition to field work at Eagle Cave we have been preparing in another way by spending some of our free time reading over the previous excavation reports on the site. The first is on excavations carried out in the 1930s by the Witte Museum, and the second discusses excavations conducted by the University of Texas in the 1960s as part of a salvage project related to the creation of the Amistad Reservoir. I have particularly enjoyed looking at the photos from these excavations. The scenery stays the same through time, but so much about the people (and excavation methods) has changed!

All of that being said, we are four weeks in, our enthusiasm is still high, and nobody has lost an arm or a leg yet. So I would call our first month in the Lower Pecos a success!


By Bryan Heisinger

As the sun rises over the rolling hills east of the Shumla Campus, the thing that strikes me is how completely quiet and isolated the camp becomes when the day to day commotion of camp life is absent. Sitting on the patio rocking chair, I can stare out towards the horizon and see for miles in any direction across the rocky landscape that surrounds the Pecos River. It is hard to find any trace of civilization — this is Nature. The chirping of birds playing in the mesquite brush, the call of an occasional train passing south of the campus, and a random gust of wind whistling in the low lying shrubs are about the only sounds you will hear throughout the day. Now and again, I feel as if I stepped back to a time when Texas was young and wild. If a horse and buggy came rolling down the gravel driveway, I would be convinced.

Just a short walk up the knoll that sits behind the campus buildings, I can look south into Mexico and see the dark blue silhouette of the north east edge of the Sierra Madre Oriental mountain range looming far away in the distance.  In between the campus and the distant mountains lay close to 40 miles of dry, desolate, desert country.  From atop the knoll, I can also make out the south canyon wall of the mighty Rio Grande. Although, I can’t see the river from this viewpoint, I know the Rio is pushing her way south east through a series of bends and turns until she finally empties into the Gulf of Mexico.

When evening begins to set in and the sun begins to sink low, the sky above the campus slowly becomes a moving painting. Fantastic shades of blue, orange, red, yellow, and pink capture the upper atmosphere and mix together in a heavenly display of hue. Every night, I sit outside and watch this scene slowly fade to grey. After color has drained the sky, the constellations of Orion and Taurus begin to fill the night before me. Nighttime at camp can be eerily silent and very dark. It seems as if the strange creaks and noises from the buildings let loose when the sun goes down, just to keep me on my feet.  Nevertheless, I manage to sleep in the bunkhouse quite well.

The surrounding landscape is primitive, but the campus is more than accommodating to the crew’s contemporary needs.  With a stocked kitchen, wireless internet, and full library it is very easy to live far away from the city and be completely content.  This place will live fondly in my memories for the rest of my life.

Shumla Campus

Shumla Campus by Isaac Martinez

The Structure from Motion Revolution: Digitally Documenting the Archaeology of Eagle Nest Canyon

By Charles Koenig

In several previous posts we have mentioned the use of Structure from Motion (SfM) photogrammetry during the ENC project.  Before I begin explaining what SfM is, I want to explain how we (ASWT) came to be using SfM on the ENC project.  I was first introduced to SfM at the 2009 TAS Annual Meeting in Del Rio.  I had just received my BA from the University of Colorado in May 2009, and had only 5 months of field experience as an intern working with SHUMLA—in other words, I was young and impressionable.  I attended a presentation by Mark Willis where he explained how he used Microsoft Photosynth to create a 3D model from photographs he took using a hand held camera (for more info see Mark’s Blog:  To me, Mark was describing something straight out of video games and movies, and I remember thinking how cool it was that archaeologists were creating 3D images using just a camera!

Dr. Black’s (Steve’s) 2010 Texas State Archaeological Field School was the first time I was able to see Mark in action.  That summer I was finishing my internship at SHUMLA and gearing up to enter graduate school under Black at Texas State.  The field school was headquartered at the Shumla Campus on Jack and Missy Harrington’s Shumla Ranch and I was taking the field school unofficially as a SHUMLA representative.  Back to Mark in action.  He suspended a simple point-and-shoot camera about 100 feet up in the air from a kite and mapped the upland stone alignment site of Javelina Heights, which the field school was excavating.  The basic principle by which a 3D surface is created using SfM is to take dozens—or sometimes 1000’s—of overlapping photographs of the object/area being mapped.  These photographs are then put into specialized software that matches each photograph up to other photographs of the same area, and it builds a 3D surface from the 2D photographs.  This 3D surface, which is essentially a topographic map, can then have geo-referenced real-world coordinates (e.g., meters or UTM coordinates) assigned to the model so measurements can be taken from the surface.  Mark spent only a few hours on site, but he was able to produce a higher-resolution site map than the one we produced after 5 weeks and 1000’s of topographic shots with a Total Data Station.

A small sample of imagery captured from Javelina Heights (left); Mark Willis and Steve Black discussing rigging a camera to the kite (top right); Mark Willis flying a kite in the Lower Pecos (bottom right)

After Mark’s mapping of Javelina Heights on I was convinced—Steve slightly less so—that SfM was the way to go.  Again in 2011 Mark came out to Dr. Black’s field school and used a kite to map Little Sotol (a terrace/rockshelter burned rock midden along a tributary to the Devils River where the field school was held).  That year my fellow Coloradoan and graduate student Ashleigh Knapp and I were the field school teaching assistants and developing our Master’s thesis research projects (Little Sotol for her, the survey of Dead Man’s Creek drainage for me).  I began to experiment taking my own SfM shots of different rockshelters I recorded as part of my survey, and even with just my basic understanding of the technique I was able to produce 3D point clouds of rockshelters.  My early efforts were mere baby steps compared to what Mark was doing at Panther Cave as part of SHUMLA’s 2011 Field School (  But, Mark’s work at Panther Cave coupled with my own experimentation was enough to convince Steve that SfM could be used effectively to map sites.  So, in 2012, during continued research along Dead Man’s Creek we began to use only SfM to map and document our excavations at three burned rock midden sites.

SfM models of Hibiscus Shelter (left) and Tractor Terrace (right). The model for Hibiscus was created using 950 photographs, and the Tractor Terrace model produced using 750. The photographs for both models were taken after excavations were completed.

After our work in the summer of 2012 along the Devils River, my TxState coursework was completed and I returned to SHUMLA to work part time as I completed my thesis; but, SfM was not forgotten.  At SHUMLA we began to produce 3D models of all the sites where SHUMLA was recording pictographs.  In part because we were constantly face to face with 3D models of archaeological sites, we began to realize what we were creating: a digital, interactive record of Lower Pecos archaeology. We were creating something that could be shared with the world.

As for me, I finished my MA in December, 2012 and worked full-time at SHUMLA through August.  I was one of the rock art instructors during the TxState Archaeological Field School at Eagle Nest Canyon that Steve co-directed with Carolyn Boyd.  I am now back at TxState working for ASWT as the project archaeologist and Steve’s second-in-command.

Fast forward to 2014 and the Eagle Nest Canyon project. We are using SfM to document and model sites, excavation units, excavation layers, profiles—essentially we are using SfM to photo-document anything and everything.  Depending on the size of the area being mapped, we can produce 3D surfaces with sub-millimeter accuracy.  In fact, SfM produces results rivaling LiDAR, but for a fraction of the cost.

With the help of Mark Willis, we have taken photographs from a UAV and remote controlled helicopter to create maps of the Eagle Nest Canyon area with centimeter resolution.

UAV imagery from Eagle Nest Canyon, courtesy Mark Willis.

Using cameras suspended from a pole (PAP, pole aerial photography), we have mapped the talus of Skiles Shelter and the floor of Eagle Cave to sub-centimeter resolution.


Charles using PAP to map the surface of Eagle Cave (top left); Jacob and Charles running PAP in Skiles Shelter (top right); a 3D surface of Eagle Cave generated from 1800 photographs.

Using just a hand-held camera we have modeled all of our excavation layers and profiles so we can better understand the deposits of the sites we are excavating.

The crew works together to photograph a 1.5m deep profile in Skiles (top). The 3D model (bottom) was created from 85 photographs.

Archaeological excavation and testing is inherently destructive—we are excavating intact deposits that once we are finished will never be intact again.  Using SfM, we are able to create a 3D record of not only the archaeological sites, but also the archaeological process.  By creating 3D records of each layer, level, and excavation unit we can digitally preserve things that are destroyed through the course of excavation.

This is a goal shared by SHUMLA and Texas State’s ASWT Project, and we are both striving to create a 3D digital record of Lower Pecos Archaeology.  From burned rock middens to rockshelters and from pictographs to painted pebbles, we are collaborating to document as many sites and artifacts as we can using SfM.  Imagine a video game-like environment where you navigate into an unexcavated rockshelter, and walk over to an area where we are currently conducting excavations.  With one click of a button you can begin excavating the site just like we did – one layer at a time.  Inside every layer you can appreciate the artifacts, look at the rodent burrows, and ponder the microstratigraphy.  Once you finish looking at the dirt, you can turn your attention to the pictographs along the rear wall and begin exploring the data recorded by SHUMLA.

We have an obligation as scientists and stewards to both study the archaeology and preserve it for future generations—SfM provides us with a means to begin creating a digital archaeological record to be accessed and studied for generations to come.

Geoarchs in Action: Dirt by Many Other Names

By Steve Black and Jake Sullivan

Yesterday’s blog mentioned that geoarchaeologists Charles Frederick and Ken Lawrence would be with us in the field today.  For an archaeologist it is often a humbling experience to have a geoarch look at the same dirt you have been digging through and staring at for days—the things they see that we don’t!  They have both archaeological and geological training and whereas we ‘pure’ archaeologists look for cultural layers and cultural things, they look first at the natural formation processes.  How and when did the layers form, and how were they transformed since being created by the hand of man and the myriad vectors of ‘bioturbation’?  This may seem easy enough to decipher with a simple layer-cake stratigraphic profile, but what we have in the rockshelters of Eagle Nest Canyon is anything but simple—convoluted layers chopped up and partially blended by burrowing animals, insects, and the pits, fires, and scratching around that peoples ancient and historic have done.  Let’s introduce our collaborators of the geoarchaeological persuasion.

Dr. Charles Frederick is regarded by most as the preeminent geoarchaeologist working in Texas today and arguably one of the best in the world.  He earned his Ph.D. at UT-Austin under the famed geographer Karl Butzer and he has worked all across Texas and many other places in the world.  Charles taught in the University of Sheffield in the UK, but returned to Texas where he is an independent consultant who works as a subcontractor for many different firms and organizations.  What sets him apart is his encyclopedic knowledge of geology, pedology (study of soils), and natural science in general.  That and the way he approaches any research project—with an open, critical mind and the belief that something useful can be learned if you pose the right questions and link the big picture to the nitty gritty details.  Charles is a true scientist, he forms hypotheses (trial explanations) and then he tries to test them by seeking the hard evidence that could either disprove or strengthen the notion. 

His comrade in arms on this trip is Ken Lawrence.  Ken earned his M.A. at Texas State University where he studied under geoarchaeologist Dr. Britt Bousman.  He works for SWCA an Austin environmental consulting firm.  But like Charles he is here volunteering his time to help us because he likes the challenge of working in an area where few geoarchs have ventured. The chance to do pure research unfettered by regulation and the bottom line.  Ken, too, appreciates the opportunity to be able to spend time in the field with Frederick.  Geoarchaeologists often find it a bit frustrating to work with the unwashed (archaeologists who lack geological training) because we speak different lingo and we don’t look at the dirt through the same lens.  Watching the two of them bounce ideas and observations off one another is quite educational.

Their mission for the next several days is twofold.  First and foremost is helping Dan Rodriguez, the Texas State graduate student who is studying Kelley Cave and adjacent Skiles Shelter for his Master’s thesis. Last week Dan and fellow grad students finished digging a 1-x-2m unit in Kelley, or at least he took it as deep as they could practically (and safely) go – a bit over 7 feet deep. When the digging was done, Dan carefully cleaned several of the profiles (walls) and took many overlapping detailed photographs using LED light panels to illuminate the dark confines.  This week Black cleaned up the walls a bit more and sprayed them down with a fine mist.  Dan’s dry photos show some things well, but wetting the walls makes many subtle and obvious details ‘pop out.’  So we took another round of several hundred overlapping LED-lit close-up photos and through computer magic stitched these together to form geo-referenced mosaic and 3D model using the Structure from Motion (SfM) approach pioneered by our collaborator and archaeo-geek extraordinaire Mark Willis.  But we’ll tell more about Mark and SfM in future posts.

Today Frederick, Lawrence, and Rodriguez spent all day in and out of the Kelley Cave excavation unit, carefully and minutely examining the stratigraphy (layering) and spotting details neither the photos nor our archaeological eyes had seen.  Ken and Charles took turns in the hole, each annotating the printed photomosaics with their take on the layers.  Dan watched from above and annotated his own set, asking questions and trying to put the geoarch’s observations and explanations in the context of what his excavations had encountered. And we haven’t even mentioned the sampling.


Ken Lawrence annotating the stratigraphic layers present in the profile.

We should explain that one of us was also present and madly taking notes.  I (Jake) have been tasked by Dr. B (Steve) to make myself useful to the geoarchaeologists, now and as the project unfolds. My minor at Texas State was Geology, so I have an inkling of what they are doing. Both Charles and Ken expressed that the Kelley profile is as complicated and messy a profile as they have ever seen. Their goal is to take as many samples as possible to try and deconstruct how all the sediment came to be in the shelter. According to Charles, the sediment could be alluvium from the Rio Grande, alluvium from Mile Canyon, soil from above the shelter on the canyon rim, and possibly even from swallow and mud dauber nests.

Ken began by taking samples from within the north profile’s different stratigraphic layers. Using a trowel he dug as far into the layers as he needed to fill the quart sized sample bags. Once Ken was finished Charles took several micromorphology samples called micromorph blocks. The blocks are handled with the utmost care, wrapped in toilet paper and tape to help maintain their structure. These intact cubes of sediment can later be impregnated with plastic, and once impregnated they can be shaved into thin sections for microscopic analysis. Ken and Charles hope to piece together the jigsaw puzzle of depositional processes within the rockshelter by analyzing the dirt’s composition. Today was the first step towards that end.


Dr. Charles Frederick packaging a micromorph block.

Above we said that the geoarchaeological mission was twofold.  Part two is the big picture: how did the deposits within Eagle Nest Canyon form and transform over time and how did the landscape itself form and weather the passage of time?   OK, threefold: Charles and Ken are also here to help us strategize how we will investigate Eagle Cave, the biggest of the canyon’s rockshelters, over the next few months.  We have formed our basic research plan, but they will help us figure out how we can maximize the amount of data we can collect as we document and sample the rockshelter’s discontinuous stratigraphic profiles.  Data that will speak to the big picture and inform us as to the nitty gritty.  Stretching before our research eyes are many forms of dirt by other names.


Expedition Collaborators

By Steve Black

Archaeology is inherently collaborative, especially on a major project like the Eagle Nest Canyon Expedition.  And that for me is a cat’s meow – building and working closely with a stellar set of collaborators. For us it starts with the landowners, Jack and Wilmuth Skiles, who for over 60 years have protected the archaeological sites we have the privilege of studying. Their house overlooks the canyon and they follow our progress closely, helping in every way they can.  Jack’s 1996 book, Judge Roy Bean Country, tells the history of the area through colorful vignettes he learned by interviewing old timers and digging into old newspaper accounts and court records.

Readers of this blog have already met or will soon meet our core crew members as they take turns making blog entries and add a bit about themselves.  Today is my day to chip in.  I am an assistant professor of anthropology at Texas State University in San Marcos, and I have been doing archaeology mostly in Texas since I was an undergraduate at UT-Austin in the mid-1970s. I am also one of the editors of, where you will find several online exhibits on the archaeology of the Lower Pecos Canyonlands. If you are just learning about the area, start with the exhibit by that name,  For an introduction to our canyon, see where you can learn more about “The Land and Its Caretakers” and take a “Virtual Tour of Mile Canyon.”  Eagle Nest Canyon is also known as Mile Canyon because it is about a mile from the mouth of the canyon to its abrupt ‘box’ head.  Back to our collaborators.

The Shumla Archaeological Research and Education Center is our key partner on this project.  Under the leadership of Dr Carolyn Boyd, the Shumla School has built an amazing program of hands-on education and systematic rock art research right here in the Lower Pecos. Shumla is based in Comstock and our field headquarters is the Shumla Campus on the Shumla Ranch along the lower Pecos River about 15 minutes east from Langtry.  Shumla is contributing to this expedition in many other ways.  Two of our crew members, Jeremy Freeman and Vicky Muñoz, are Shumla staff members who are ‘on loan’ so to speak as part of Shumla’s Border Canyonlands Archaeological Project.  Shumla also loans us critical equipment such as a total data station and helps provide field transportation.  Our partnership with Shumla helps underscore the multi-faceted nature of Lower Pecos archaeology – the rock art on the rockshelter walls and the chewed up lechuguilla quids we find beneath the surface are part and parcel of the ‘whole enchilada,’ meaning the lives of the Indians that called the canyon home for so many generations.

In future entries we will introduce many of our other collaborators, such as the visiting experts who are taking part in our research project and our fellow archaeologists who come down to volunteer.  This week, for instance, retired archaeologist Daniel R. Potter is lending a hand and keeping the crew entertained with jokes at my expense.  “Steve, you need to put your hat back on—the glare off your dome is ruining the photo.”  Tomorrow geoarchaeologists Charles Frederick and Ken Lawrence will help us unravel and sample the complicated depositional history revealed in the stratigraphic profiles we have been exposing.  Like I said, working with so many wonderful collaborators is the cat’s meow!  (And I don’t mean the plaintive cry of Mystery, a young feral cat that has appeared in the canyon and demands sustenance—cheese sticks don’t seem to do the trick.)


Jake, Brooke and Bryan overlooking the Pecos on Shumla Ranch