The Great Debate: How old ARE the Footprints at White Sands? with David Rachal and John Taylor-Montoya
[00:00:00] David Rachal: One thing (intro music begins) about these footprint studies, they really do paint this utopia. It’s like the sloth human paper where they, they were having a good time and they’re making fun of the sloth. It’s like a Monty Python skit, you know? And that may be true. I don’t know.
[00:00:12] John Taylor-Montoya: You know, humans really aren’t out there, you know, just in their birthday suits, you know, bare feet with nothing else with them, you know, romping around the mud flats with sloths. They’re usually out there for a reason and they usually have things with them. A lot of archeologists often question, okay, well, you know, why don’t we see something like a hearth? Why don’t we see stone tools that we can recognize?
[00:00:32] David: It’s about origins, and origins is always pretty sexy. I mean, we’re at the cusp of a potential paradigm shift for sure.
[00:00:40] Emily Withnall: ¡Bienvenidos! This is Encounter Culture from the New Mexico Department of Cultural Affairs. I’m your host and editor of El Palacio Magazine, Emily Withnall.
(intro music fades away, shifts to groovy guitar music)
Ever since I heard that there were footprints at White Sands that had been dated at 23,000 years old, far older than humans were thought to be on the North American continent, I was captivated. Admittedly, I did not read any scientific articles about this at the time, though I did peruse magazine articles that covered the topic—including of course, an article in the summer 2023 issue of El Palacio, linked for you in the show notes. And it seems that everywhere I go now I hear that human life on this continent is older than we thought. Most recently, I even heard an artist visiting Santa Fe mention it during an event.
Clearly, I am not alone in my amazement. What if the footprints are 23,000 years old, and what would that mean about everything else we know?
Humans are hardwired for storytelling, and there is nothing better than encountering an unexpected plot twist that upends everything we thought we knew. To that point, whether we are learning about new technologies or using those technologies to look backward at the past, science often delivers exciting stories, possibilities, and new ways of understanding the world.
But what is less talked about by non-scientists is how very messy science is. Besides the fact that humans are limited by what we can perceive and how those perceptions are shaped by our environments, science is constantly in motion. Often, as soon as we make one discovery, we learn more that challenges or complicates our previous understandings, or new discoveries shift the questions we were asking to begin with.
As with any scientific inquiry, the story of the White Sands footprints is not over, and the research that has been done so far is incomplete. To talk with me about why this is the case, I was joined by Dr. John Taylor Montoya, director of the Office of Archeological Studies, and Dr. David Rachal, geoarchaeology consultant in southern New Mexico.
Together they explain why there are two different schools of thought on how old the footprints are, why carbon dating isn’t always conclusive, and what still needs to be researched to determine how long humans have been in North America.
And just a heads up: We’re going to be referencing a few photos from the site in this conversation. If you want to see them for yourself, please visit the show notes for this episode at podcast.nmculture.org.
Admittedly, when I heard the footprints might not be 23,000 years old, I was deflated. And to be honest, given that the research is ongoing, I still hope it’s true because I’m hooked on the plot twist. But perhaps listening to this conversation will lead you to a deeper appreciation of how differing perspectives in the scientific community are a secret superpower.
(music fades away)
[00:04:20] Emily Withnall: Welcome to Encounter Culture. Thank you both for being here with me. Do you wanna start us off with some brief intros of who you each are?
[00:04:27] John: Sure. I’m Dr. John Taylor-Montoya. I’m the director of the Office of Archeological Studies, and I’ve been studying people in the Americas for close to twenty years now.
[00:04:36] David: I’m Dr. David Rochelle. I’m a geoarchaeology consultant in southern New Mexico, and I’ve been doing geoarchaeology work now for about twelve years. And I’ve been working on the White Sands footprints in the Tularosa Basin off and on since 2014.
[00:04:53] Emily: What was the earliest sign for each of you that you would go into your respective professions? So, for example, did seven-year-old David know that you wanted to do what you’re doing now?
[00:05:02] David: I think twenty-year-old David knew what he wanted to do after taking his first geomorphology class. So yeah, twenty years old, it’s what I wanted to do, and I don’t even know why I was into fossilized soils. It’s such a nerd thing, but, uh, I dunno. I’m having fun. Hopefully it continues.
[00:05:18] John: For me, it started out pretty early, so I’ve always been, you know—art has been a love of mine, but also, you know, I’ve been fascinated by archaeology since a young age, and I remember checking out books in the library, in elementary school. I think even before I could read, I would just look at the pictures of King Tut’s tomb and things like that, so—I thought I was gonna be an Egyptologist, though (everyone laughs).
That’s what I thought. And of course, now my role is a little bit different. So, as the director of the Office of Archeological Studies, you know, I’m actually in charge of a much broader research program where we don’t do just one particular area. We do all kinds of different studies of all different time periods here in New Mexico.
But that’s, again, why I’m glad that, you know, Dave is still out there, fighting the good fight and doing the good science because this is something that is still very much an interest to me.
[00:06:07] Emily: Okay. Well, that’s a perfect segue because I wanted to start off by asking you both: When were the footprints discovered in White Sands, and who discovered them?
[00:06:18] John: Ooh, that’s a good question. So, when we first encountered them, we were working together on White Sands Missile Range for the, for the army actually. And Stan Berryman was the archaeologist who was contracting us for the army to work out there. And he brought it to our attention. The footprints were initially reported to my knowledge in the early 20th century, and in fact, they were reported by a hunter who had been out there. And they were referred to back then in the newspaper article as Bigfoot prints.
But shortly after that, they were verified as something other than Bigfoot prints. And the army had actually built a fence around that particular little area of footprints on the range. And to my knowledge, not much had been done with those footprints, with anything on the range until, you know, Stan contracted us specifically in 2014 to go out there and do a systematic survey of the footprints themselves and also any paleontology we might encounter out there and of course, you know, the geology and geoarchaeology of the area as well.
[00:07:22] Emily: Okay. So, what was your reaction when you first saw them?
[00:07:26] David: “Wow.” (Everyone laughs) I mean, it’s pretty cool that, you know, these footprints can be recorded. They’re twenty-something thousand years old and they’re just right there at the surface.
[00:07:37] John: And I have to say, just, we had a team out there and so it was Dave and I and a couple of other scientists and all of our reactions I think were “Wow!” at the time.
[00:07:45] David: And a photo of them is, uh—can you bring up photo one please? So that’s the set of sloth tracks that we worked on with our project in 2014, 2015. Yeah, they’re, I mean, I could see where someone could come out there and go, “Ah, these are Bigfoot tracks.” Pretty amazing. They’re kidney-bean shaped. They have a pretty long gait, but that’s a sloth walking upright a very short distance.
[00:08:10] Emily: Yeah. And so, listeners can kind of visualize this, the footprints are kind of, they’re not imprints, they’re what—what’s the reverse of that? They’re a cast, yeah. It’s, like, elevated above the actual surface of the ground.
[00:08:25] David: Yeah, they’re, they’re huge. Now, one thing about the prints, when you find them in that elevated context, what that’s telling you, there’s been a lot of wind erosion and the original surface has been removed away. And then the, the print, which was originally pressed into the soft sediment, which was the topographic low, has been inverted to the topographic high, right?
So, when you’re out there walking around, the original service of both human beings and the megafauna walked on has long since been gone, been removed by erosion.
[00:08:54] Emily: Right. So, in terms of these being actual sloth prints, I have a couple of questions about that. One, don’t sloths have claws? And also, those are so far apart, so those are not like current sloths. Right? Like the sloths that we have on our planet right now?
[00:09:10] John: That’s correct. Yeah, so these, these, these would be giant ground sloths, so an extinct form of sloth that would’ve been around during the late Pleistocene, not only here, but throughout the Americas. And yes, you know what Dave just said is very important.
You know, our listeners should keep that in the back of their minds for this entire conversation as we go forward. This is a very dynamic landscape and the gypsum sediment that these prints are made in is very friable, meaning that it’s easily crushed or, or malleable, and also water-soluble. And so, you know, you have to think of this area as being waterlogged or damp. It’s a lake shoreline or near a lake, or actually, you know, underwater at times.
And so, as the animals are moving around in there, sometimes the prints that they make, you know, aren’t those nice little, like, you know, cement casts that you make with your kids for the garden. You know, you put their little hands or their feet in there, they make a nice little cast of their hands. The animals, these large, heavy beasts are sliding around in mud sometimes. That’s one of the things that you have to contend with out there. But there are many that you can’t identify to the type of animal—camel, sloth. The elephant footprints are kind of unmistakable out there. Those are ones that are pretty unambiguous.
[00:10:23] David: So, the most common are the elephant tracks. And that’s just because they’re really big animals and they, it’s real easy for them to leave a trace. But you can find a saber-tooth tiger, or a North American lion. Or dire wolves, which I think there’s a, those things are really hard to identify and, you know, they’re supposedly out there. Sloth tracks.
It’s pretty remarkable. And a lot of times, you know, when you see these surfaces, particularly when they’re pedestal, you know, you have to keep in mind that you’re looking at a palimpsest surface. These trackway surfaces are very thin. Erosion comes through and removes the sediment, and it’s exhuming the surface, it’s eroding out the tracks, and a lot of the tracks are popping up differentially.
So, you could be looking at two or three different track surfaces superimposed on top of one another. It’s really, really complicated.
[00:11:09] Emily: Okay, interesting. And there are human tracks among the sloth and, and elephant and dire wolf and everything that you just mentioned.
[00:11:18] David: Yes. But it, you know, it’s a question of: If the human footprints are impressed into the sediment and they’re around megafauna, tracks that are pedestaled, they might not have formed at the same time. They might not be associated.
[00:11:31] Emily: I see.
[00:11:32] David: And, and that’s just because it’s a complicated landscape. Gypsum’s tricky. It’s a soluble mineral, so it will move around a lot. Now there are areas where you have intact surfaces and it’s very possible that if you find human footprints in that area of those types of tracks, and they, they could be cutaneous. Meaning the same, same age. You know, typically a geoarchaeologist goes out an archaeological site. You know, we want to know if the artifacts have been moved around a lot or in the original place, right?
When the geoarchaeologist goes out to track ways, they have to assess if the, the human tracks and the megafauna tracks are coetaneous and what that means. Did they form at the same time in the geologic record? And that’s a tall order because there’s so many things going on out there. There’s a lot of erosion and sedimentation. Surfaces can get exhumed and then buried again, and it can, it can be misleading. It can be very, very tricky. So, that’s what I mean by coetaneous.
(Futuristic music plays)
[00:12:36] Emily: So, I know that part of what we’re talking about today is maybe, I don’t know if it would be correct to characterize it as a scientific debate or conversation around the dates of the actual human footprints and how we know how old they are or what the process has been to discover how old they are.
[00:12:58] David: I would say “debate.”
[00:12:59] Emily: Okay. Debate!
[00:13:01] David: It’s not a conversation. We’ve passed that point. (Everyone laughs) Uh, I would say a debate, and I think, you know, no one is arguing that they’re not Pleistocene in age, right? They are, right? The argument is about: Is it last glacial maximum? And that’s around 25,000 years ago to 20,000 years ago. That’s during the last Ice Age.
At that time, you would have massive glaciers coming down, covering up a lot of the upper Midwest in New Mexico—it would look a lot like Silver City, that drive from Silver City up to Glenwood, where the trees would be lower down the mountain slopes. You would have grassy basin floors and the lake would be present, right?
That’s the last glacial maximum. The other argument, or the other idea, is that, well, maybe they’re Terminal Pleistocene, and that’s around 15,000 to 12,000 years ago. And, uh, we have a lot of data to support that. We have no data to support that idea that, uh, people came down here during the Last Glacial Maximum.
So that’s the argument: whether they’re Terminal Pleistocene or Last Glacial Maximum.
[00:14:02] Emily: Okay. Okay. What are the different ideas or thoughts about how old these tracks are and what’s the difference between those?
[00:14:11] David: So, what we think we know based on genetic models, the physical archeological record of North America, and you know, these geologic studies that showed when these migration corridors opened up, that people were here sometime around 16,000 years or later.
So, if we were here 21- to 23,000 years ago, you know, we’re missing—we’ve missed thousands of years.
[00:14:34] Emily: Okay. But there are some scientists who are saying that the tracks might be that old, the 23,000?
[00:14:40] David: Yes.
[00:14:42] Emily: Okay. So, are there two camps then around this, this debate?
[00:14:47] David: Well, there’s a Rebel Alliance, which is made of a few other people, (everyone laughs) and you know, there’s, there’s the, the empire. I’m just joking!
Uh, you know, uh, yeah, there’s two camps. That’s right. For sure. My biggest beef, I don’t care if people were here 23-, 21,000 years ago. Right? My biggest beef is it’s about the plant and what they’re dating. It’s not how they’re dating it.
Radiocarbon dating is really well-known. It’s a really respected technique. It’s been around a long time. It’s just about the plant. The plant has a bad reputation for being unreliable. And the other issue I have is the context of the seeds themselves.
[00:15:19] Emily: Okay, so let’s dive into the seeds. So, can you kind of give an overview about how these footprints are being dated?
[00:15:27] David: Can you bring up photograph four? That’s a picture of the upper left, is a picture of the seeds. The bottom one is the seed layer that they’re dating. So, they’re in this mudflat deposition type of environment, and mudflats are really great places to have the preservation of footprints because mudflats are submerged when the lake is really, really high.
If the lake dries out, then the mudflat’s exposed, and when it’s exposed, all it is is just spongy, soft sediment that’s composed of silts and clays. So, when the megafauna or people walk across it, their footprints just squished down into it. And if the lake rebounds or say wind blows in onto that tracked surface, or if there’s a river by it that floods and drops out sediment, it buries the prints.
So, if that process repeats over time, it creates a stratified record of human footprints. And that’s what we’re seeing at locality too. That’s their site that’s really gotten a lot of critical acclaim. Now in that you have these seed layers, so you have footprints that are stratified and in between each one of those footprint-tracked horizons, you have seed layers like up there in the upper left, and they’re composed of Ruppia cirrhosa seeds.
And Ruppia is an aquatic plant. It lives underwater. And it has a bad reputation for being unreliable because it can’t really use atmospheric CO2 for photosynthesis. It doesn’t get its carbon from the atmosphere. What it does is it gets the carbon from the water, and that water is artificially old because it’s contaminated with bicarbonate from the limestone in the basin.
So, it pulls in that artificially old carbon during photosynthesis, that carbon gets pulled into the plant’s tissue, and if you radiocarbon date it, it’ll come back thousands of years older than what it’s supposed to be. So, okay, can I finish with one more thing?
[00:17:17] Emily: Yeah!
[00:15:18] David: I just wanna take it home here. Alright, so, if we all three got in a car and we went to the Tularosa Basin right now and we go to the Salt Creek where Ruppias still grows and I get John some waders and he’s out there and he picks a bunch of plants. We send it off for radiocarbon dating. That modern plant can come back 8,000 years older than what it’s supposed to be.
[00:17:36] Emily: Wow.
[00:17:37] David: Now it is variable, it is variable. If you go around different parts of the little wetland you sampled, it could range anywhere from 2,000 to 9,000 years old. So, it’s, it’s unreliable, and that’s a big issue and that’s a scientific fact.
[00:17:52] Emily: Interesting. So, are there other ways of dating things?
[00:17:56] David: Let’s talk about the second issue first, okay?
[00:17:58] Emily: Okay (laughs).
[00:17:59] David: The—so, you got this plant that lives underwater and it pulls in old carbon. It can look really, really old and it can be young, right? It’s not a good material to base a chronology on, and typically the general rule of thumb is just stay away from it, right?
The other issue about the plant, it’s how it propagates. It’s underwater, and during certain times of the year, it grows little flowers. And these flowers are designed to break off if there’s just the slightest bit of turbulence. So, if it’s flowering and a storm comes through and the water’s shaking, the plant will break apart, and all of those stems and seeds create these floating maps.
Once it does that, it turns into the tumbleweed of the lake. It can float up to days, weeks, to months, and it can go from one side of the lake to the other. So, what happens is the plant’s breaking apart—it can be washed in from the west side onto the east side, into their site, and being deposited into the trackway site.
And we know that because we’re finding lake balls. Those are those Ruppia seed balls there. And that’s from the plant breaking apart, being pushed across the lake. It gets caught up in the tidal zone and wave action rolls them into balls and it mixes all that material into these little spheres. It could be the size of a ping pong ball; it could be the size of a baseball.
But the point is the plant didn’t grow in the sight. It’s coming in from deeper water.
[00:19:25] Emily: Interesting. So, just so that I’m clear, are you saying that there might be stratified footprints that are already kind of layered and then the seeds are kind of seeping in or—
[00:19:38] David: They’re being washed in by storms. So, you have this scenario where it’s, you have people walking across the shoreline and you’re getting all this artificially aged material injected into their footprints. What that does is it makes them appear older than what they really are.
[00:19:56] Emily: I see. Okay. Interesting. Okay, so we have these seeds that are hard to date. We have the movement of the seeds across the water. Is dating the seeds the only way to tell how old the footprints are?
[00:20:12] David: Ooo, well, that’s all you got. And it is not that people haven’t tried to find terrestrial material—that’s really the only way to get around the hard water effect, is that you, you need to find something terrestrial to compare the aquatic seed dates to, right? So, if you find, say, charcoal or maybe some insect part in a sea layer and you date that, and then you compare that to the aquatic seeds, if they’re the same age, then you know that the hard water effect wasn’t an issue at the time. But if there’s a difference in age by 8,000 years, then the hard water was present, and you can use that to correct the age.
[00:20:51] Emily: Okay. Okay. So, and just so listeners are aware, the hard water effect is what you were just describing about the limestone or the older elements being absorbed.
[00:21:03] John: Mm-hmm. Yes. You have carbon in the water derived from these ancient limestone deposits. And so that’s, of course, you know, those are potentially millions of years old. Theoretically, there are a lot of different ways that you could attempt to date an archeological site.
And what Dave is getting at here is that, you know, unfortunately, you know, what you are at the mercy of is, is what is deposited at the site. Because again, we want to get to this question of association, and this is a fundamental question of all archaeological sites and dating things, no matter what they are or what material you’re dating: Is the material that you are trying to derive a date from, was it deposited the same time as the object or thing that you’re trying to actually get a date for?
But again, getting back to the theme that we had mentioned in the beginning: So, locality too is a pretty good depositional environment, but it still is subject to these geological processes that can sometimes fool us.
My former advisor, when he was talking about this debate, said something very simple but very apt: Mother Nature has a way of fooling us sometimes. And then you have a material that they’re using to date the site that is not necessarily reliable. So, you have these three different areas that all have their variables. And one of the things that Dave and I, from the very beginning, when we were out there studying in this area in 2014, is, you recognize the fact that this is a very complex area with some very complex problems that you have to go through as a scientist, before you can get to the fun stuff and of interpreting the archaeology and paleontology that you see out there.
So, first principles things. How the site was formed—you know, what are the different processes, what are the variables, and can you control for all of those different variables. And can you explain them or can you correct for them? And so, our approach from the very beginning—and this is something that Dave has carried forward in his research now—is, you need to approach it from that perspective of, “Let’s discover first, you know, what are the processes that formed what we’re seeing, what was deposited out there, and how it looks to us today because how it looks to us today may have been altered from what happened in the past.”
And so, what you think you are seeing on the surface today may not be a reflection of what happened in the past that you can take at face value. You first have to do all of that detective work in order to get to that story. You know, there is this debate about the dates, but there’s also, you know, two different kinds of approaches on how to solve these problems. And I’m kind of biased ‘cause, you know, Dave is a colleague and someone I worked with in the past. But I think we worked well together because we’re cut from the same cloth in terms of how we look at the problem.
(Music continues, then fades)
[00:23:55] Emily: So, there’s a lot to respond to there and to ask about, but I want to kind of circle back as I’m thinking about this debate as it exists to something you said, David, about being the “Rebel Alliance.”
(Everyone laughs)
So, I’m curious if you are the underdogs in this debate and why that is, or what the counter argument is when you present all of this research about the seeds and the problem with dating them.
[00:24:21] David: I’m gonna riff off what John was talking about here. The context is critical because they argue that the plant grew within the site, and if the plant grew within the site, you know, there’s all these assumptions.
If it grew in the site, in shallow, aerated water, and the water was fresh, then the hard water effect is not an issue, right? If the plant washed into the site—that’s our model, right? If it washed into the site from far-off sources, it’s still subject to the hard water effect. And if that’s the case, the chronology’s off by an unknown amount. We don’t know for sure. We’re gonna figure that out. That’s the issue.
The whole context of that plant is what the debate’s around—their cornerstone of their argument is that that plant grew within the site. But when you go out there and you look at the seed layers and you look at the plant bits and parts, the only thing that you find there is the tumbleweed part of the plant. You don’t find roots or other parts that suggest that the plant was there growing in a cecil way. Instead, all you get are the stems and the seeds, and all that tells you is that it washed in. And that’s the big argument, this controversial context, and we keep going back and forth on that. Probably it will never go away until we find a piece of terrestrial carbon in a seed layer, and we’ll see which way it goes.
[00:25:38] Emily: Interesting. Okay, so, part of that difference in opinions in that argument is also based on water levels, right? So, is there any way to know what the water levels were?
[00:25:50] David: Yeah, just examining the stratigraphy. I mean, we know based on the stratigraphy of the site, the footprint site that the lake was pretty low. It was in this phase of where the lake was regressing, it was dropping. Right? So, and it had to be low. I mean, as it was dropping, of course there’s times where it would rebound, but it was generally drying out. And that’s when you have those exposed mudflats and that’s a really good time to have footprint preservation.
Well, as that’s happening, you’re having storms and the plants being broken apart, and it’s being washed from one side of the basin to the other and being injected into their site.
[00:26:27] Emily: Right.
[00:26:28] David: And that could make it look older than what it is. And this happens. This is, this is not, like, some crazy idea. At Little Borax Lake, there’s an event. Little Borax Lake, 1948. Ruppia was there. Storm came through, it busted up the plants. It washed material from one side of the lake to the other, deposited the shoreline, endohuman footprints. And that plant dated 700 years old. So, it made those prints look 700 years older than what they really were. So, it can happen.
It’s, it’s a real weird phenomenon. This has only happened like six times in recorded history. I thought this was pretty interesting after I published the paper. I don’t why I was flipping through Thoreau’s Walden book, but he talks about it in page 217. He talks about lake balls. He called ‘em “curious balls.” But, uh, it happens.
[00:27:15] Emily: Wow. Okay. So, on the one hand you have your argument that the stems and the flower part of the plant are the only things that are found. What is the other camp’s argument for why they think the plants were actually growing on the site?
[00:27:30] David: Well, good question. So, the stem is typically attached to the seed and they argue that that’s evidence of in situ plant growth, and that’s not true.
That’s like the, the fronds of a dandelion—you blow a dandelion, they fly out little parachutes, and they get dispersed around. That’s all you’re looking at. They have no evidence. We’ve tried to bring that up of, “Okay, if the plant grew there and you have all this preservation of all this Ruppia material, where are the roots?”
And all you get is, ah, you know—they don’t, they don’t respond. I mean, if the plant grew there, there should be roots. It’s a rooted plant. And if the plant did grow there, those roots would obliterate the trackway strata. Those roots would destroy that fine stratigraphy that the footprints are in.
And this is a very dynamic, laminated environment. And the evidence is just not there, that the plant grew within the site. It’s not.
(Upbeat, ethereal music begins)
[00:28:23] Emily: Okay. Wow (laughs). This is a vigorous debate.
(Everyone laughs)
(Music plays)
(Ads begin)
[00:28:34] Emily: As a child, I spent many summers hiking with my family across mesas around New Mexico. We visited the big sites like Chaco Canyon and Bandelier, but we also went to lesser-known sites like Tsankawi and the Puye Cliff Dwellings. These trips were fueled by my parents’ interest in archaeology and New Mexico history, an interest they passed down to me.
Are you also fascinated by archaeology and ancient human history? Since 1952, the New Mexico Office of Archaeological Studies has worked to identify, interpret, and share information about prehistoric and historic sites across the state. Through community outreach and educational programming, the New Mexico Office of Archaeological Studies ignites the curiosity of New Mexicans. Discover New Mexico archaeology.
To learn more, visit nmarcheology.org.
(Music continues)
Did you know the New Mexico Culture Pass is now available to purchase Online? Culture Pass gives you access to each of the 15 state museums and historic sites we feature on Encounter Culture. Whether you are a local resident or you’re visiting us on your travels, reserve your Culture Pass today at nmculture.org/visit/culture pass.
(Ads end)
(Music continues, then fades)
[00:30:13] Emily: I do have a slight side question. I’ve been to White Sands. It’s very windy. How has the wind, not in all this time, wiped away these prints or even the top layers of the prints?
[00:30:28] John: Well, I would argue that it probably has wiped away prints. And in fact, you know, that was one of the concerns that the army archaeologist had when he sent us out there, was, how are we going to, you know, preserve these for future study or, you know, how are we going to manage these?
And that was a big concern, that they’re subject to wind erosion. And because especially the gypsum is, is so friable that anything, you know, potentially could destroy these footprints. And they are. So, that is something that is happening. That’s one of the aspects of this dynamic environment, is that you do have these different areas of preservation and erosion.
And in fact, the White Sands Basin and those beautiful White Sands that we love to go to and visit are themselves, a process of those erosional events happening, you know, just within the recent time.
But if I could just take a little aside here real quickly, that gets me to one of the questions about association and the fact that you can have potentially two things from different time periods next to each other on the same surface and potentially looking like they may belong there. People not only were there in the past, but they were there continuously through the past and up and through the present and through the historic time, and you find evidence of all of those occupations on the White Sands today.
So, you have prehistoric deposits there that are a thousand years old or a few hundred years old, and um, they’re also out there, you know, amongst the footprints—tools, pottery shards, as well as prints that people are making then at that point in time out on that gypsum. You know, it’s still a malleable surface. It’s still subject to those same physical forces and properties that gave rise to the footprints that are very ancient. And so, again, we get to this picture of this, this landscape, this area that is very complex.
[00:32:22] David: And you need to interpret them in that, that dynamic context. It’s very dangerous to go out there, and you find all these surfaces and you just assume that that’s just a snapshot of what it was 20-something thousand years ago. Not to say it’s not possible, but in a lot of cases out there, those surfaces are so deflated, the prints are pedestaled. It’s hard to tell what’s going on, you know, and it can be misleading.
One other thing I wanna talk about too is that when you’re out there and you do find prints, and if you look for the physical archaeological record and the closest thing you can find are typically projectile points that are Late Archaic, you know, only a couple thousand years old, maybe Formative Period. So, when you look at the physical archaeological record near these purported human footprints, it is pretty recent.
[00:33:13] Emily: So, when I first read about these footprints, there was a lot of excitement because, you know, the early research was perhaps pointing to these being much older than when humans are thought to have come over the land bridge. So, I’m curious about that element of the debate and what makes these prints significant, even if it doesn’t disprove the land bridge theory, or if it proves something else.
[00:33:42] John: I’ll take one part and you can take the other, or you can—we can build off each other.
[00:33:42] David: Tag team.
[00:33:42] John: Yeah (everyone laughs). So, you’ve asked a really big question. You know, I don’t know if you intended it as such, but you know, this actually gets to a much broader area of inquiry, which is, you know, the people of the Americas. When did people arrive here and how did they do it? And what shape did that take? For a long time, the received wisdom and a lot of the evidence pointed to a terminal Pleistocene entry. These were a hunters and gatherers, by the way. So, these are folks who are living off the land, hand to mouth. They’re hunting or gathering wild plants for their food.
And so, for a long time, that was capped at about 12,000 years ago. Over time, there have been other discoveries that have pushed that chronology back. Additionally, there’s a lot of other lines of evidence that go into answering this question. So, this question is, isn’t just an archeological or purely archeological question—genetics has something to say about this. Linguistics has something to say about this. Geology has something to say about this. Climatology has something to say about this debate as well.
And now, you know, I think a conservative estimate would be somewhere around 15,000, 16,000 years ago is probably the early entry point when people came into the continent and then dispersed rapidly across both North and South America.
Claims beyond that are going to push that, you know, and sort of change how we think about things, force us to not only rethink what we thought we knew, but when you started getting into certain time periods, especially like the Last Glacial Maximum, you also have to rethink how they were getting here. How they were surviving because it would have to have traversed some environment, you know, in some way other than, uh, the land bridge that looked like it did, you know, at the end of the last ice age.
And so, it’s not just simply, you are talking about a different date, but you’re actually changing the entire picture of what we think we know about, you know, how the Americas were first inhabited. And this is a debate that’s been going on for a long time, you know, but it’s a very complex question.
(Dreamy instrumental music begins)
[00:35:43] David: So, as I said before, I mean the, the debate centers around whether they’re last glacial maximum 21- to 23,000 years ago, which is what we wish we knew. Or if it’s 15- to 12,000 years old, which is what we think we know.
Either way, it’s still the oldest site in New Mexico. And it’s a contender to be one of the oldest sites in North America. And I don’t think we need to lose sight of that. It’s not like I’m gonna go out there, come back and go, man, these things are like 2,000 years old.
That’s not true. No, it is a legit place to see. It’s just, does it fall into when we think people got here, or is it they got here earlier and we don’t know how, and it just screwed up decades of research? I mean, we’re at the cusp of a potential paradigm shift for sure, if this is right.
(Music continues)
[00:36:34] Emily: So, for listeners who may be thinking that 15,000 years ago and 23,000 years ago sound both really long ago (laughs), what is the huge difference between these timeframes in terms of dating these footprints, and why does this matter so much?
[00:36:52] John: Do you wanna take that on? (John and David laugh) No, I, I’ll go for it. So, I guess from my perspective, there’s a whole body of evidence in research that, you know, tends to be accepted by the vast majority of archeologists out there.
That points to a particular time when we think we know. Most likely when people, you know, first arrived in the Americas, you know, so genetic studies have shown over and over again that the modern Native Americans are genetically related to East Asian populations and probably split from an East Asian Beringian population sometime around 23,000 years ago.
And then there was another genetic split sometime around 15,000 years ago into northern Native American and southern Native American populations who then disperse rapidly across the continent. So, that’s what the genetics is showing you, that evidence. And then also, you know, as we talked about the geology and the climatology, so knowing giant glaciers that were, you know, growing in, in, in northern North America, at some points they closed up the land bridge.
At some points it was open at some points. They’re growing all the way down into, you know, the upper midwestern United States, and of course the Rocky Mountains. And so, these are all areas that if people are coming down from Siberia through the land bridge, they would’ve had to have traversed. And so, if the land bridge is closed, that’s a route that’s no longer open to them.
And so, if they are here, they have to find a new way down. So, they have to either go down the coast, the Pacific Coast, or you know, some people propose that maybe they came across the Pacific. There are also some other ideas in the past that came across the Atlantic, but again, the genetics would argue against the Atlantic crossing.
And so, you know, again, from my perspective, this would change not just the number, the date, but we would have to rethink everything about what we think we know about the first people that came here into North America. Where they were from. How they got here. How they could have possibly done it. How they survived. What it looked like when they first arrived here in North America. Because again, the difference in your environment, your ecology between 23,000, say 12,000 is gonna be huge, not just in terms of like the weather, whether it’s, you know, there are glaciers, it’s colder, it’s warmer, you know, lakes are drying or they’re high or whatever. But also, at this time you have mass extinctions going on, so the kinds of animals and plants that you would encounter would be completely different as well.
So, it, it changes everything for us as scientists who are trying to study this problem and make sense of it and gather the evidence and create these models and do our research. That’s why, you know, we talk about a paradigm shift. You know, it, it’s not just those little numbers.
[00:39:51] David: I think it’s about origins, and origins is always pretty sexy and everybody’s interested in it. The peopling of the new world, that particular field is very contentious. There’s a lot of arguing back and forth. What John saying’s absolutely right. I’m totally on board with that. I think a lot of our understanding—we have a lot of hypotheses out there that have been around for a long period of time that’ll be overthrown.
The big one is the overkill hypothesis. You know, when people show up on the scene, the megafauna, they die off, right? And if people got here 21- to 23,000 years ago, maybe even older, we don’t know, then the megafauna die off wasn’t the result of human beings. That was something else. And we don’t know what it is.
One thing about these footprint studies, they really do paint this utopia of people living with the megafauna. It’s like the sloth human paper where they, they were having a good time and they’re making fun of the sloth. It’s like a Monty Python sketch, you know? (Emily laughs) And that may be true. I don’t know. But, yeah, no, it, it’ll turn over so many things and that’s why it’s important, and it’s about origins and everybody’s interested about that. And, yeah, I don’t know.
(Futuristic rock music plays)
[00:41:11] David: You know, one thing I would like to talk about if we have a little more time, you know, the Tularosa Basin is not some random basin in Nevada. I mean it’s, there’s military facilities there. You get White Sands Missile Range. You’ve got four-plus military reservations. And both those localities, I mean, they’re at the size of Delaware or maybe Rhode Island two times over, so they’re large.
(Music fades out)
They have a CRM [Cultural Resources Management] program that’s been in effect for, who knows, forty years. There’s been hundreds of thousands of acres surveyed, tons of backhoe, trenching, testing, thousands of hearth features dated, and I, I guess when I think about the 21- to 23,000-year-old footprints, I just always go, “What are we doing wrong? How come we haven’t found that?” Because, I mean, if you have the preservation of human footprints, you should have organics associated with occupation. A hearth. You should have some, I would say—John, correct me if I’m wrong, but you would think to have some kind of lithic technology, right? And we’re not finding that.
I mean, and it’s not like we haven’t looked. I mean, I get it. It took twenty years for Louis Leakey to find Nutcracker Man. We’ve been at it for forty years and we haven’t found anything. I mean, systematically looking at it, lots of data, and I’m just, I’m skeptical, you know?
Emily: Yeah, yeah.
[00:42:26] John: So, yeah, that brings up a good point about how this fits into the larger debate. So, unfortunately, in that respect, this falls under, you know, a category a lot of other claims for great antiquity in the Americas in general fall under, which is these sites tend to be anomalous and they tend to have, you know, very, sort of unique preservational qualities to them. And so, a lot of them come under immediate scrutiny for that.
And then, you know, many of them also suffer from the fact that, yeah, you don’t have associated material culture or material culture that’s in any way sort of diagnostic or recognizable. So, what we would like to see as archeologists in general, is we like patterns, and we also like to see something that sort of fits with multiple lines of evidence.
And so that’s what Dave’s kinda getting to here. So, alright, we have this wonderful environment where we’ve got, you know, these footprints that are preserved, so where’s the other human stuff here? You know, humans rarely are out there, you know, just in their birthday suits, you know, bare feet with nothing else with them, you know, romping around the mudflats with sloths. They’re usually out there for a reason, and they usually have things with them.
And you know, I don’t know about you guys, but we leave stuff everywhere. We drop things accidentally, on purpose. I mean, that’s how the archaeological record is formed. And so, you know, for a lot of these sites, a lot of archaeologists often question, okay, well, where’s, where’s the culture? Where’s the pattern? You know, why don’t we see something like a hearth? Why don’t we see stone tools that we can recognize? You know, why don’t we see anything that you would typically expect at any other archaeological site, or in this case, like, an archaeological district?
You know, as he alluded to earlier, there are literally hundreds of acres of footprints on White Sands, and out of all of that, you know, if you do have human occupation there that’s so well preserved, why haven’t we found other kinds of evidence for it that would go along with this? You know, and again, I, maybe getting back to the earlier question of why would this be such a big deal—whatever you would find at 23,000 years ago would potentially not look like anything we’ve seen before. And so, you would be discovering, like, a new cultural tradition in North America, you know, but again, we should see evidence of that in some way, shape, or form. And so, that’s very legitimate and that’s something that is sort of at the core of, of a lot of these, you know, claims for very early antiquity, you know, very, very old sites in North and South America.
[00:44:59] David: Yeah, we need, we need to correct the hard water effect problem because that’s, it’s there to some degree. We don’t know by how much, but it is there. And then we also need to find some physical archaeological material. We do. I mean, I think that’s where we gotta go to, except this, a few critics, you know, they’re, oh, they used antler bone. They didn’t, they didn’t use stone tools. Like, I don’t know. That’s, one guy told me, and then the other person was like, oh, well, you know, they’re just walking across the landscape. They’re not going to drop anything. It’s like, well, the archaic people did. What makes the LGM folks any different? Right? We’re always on the scene mucking things up, you know, it just, it’s just what we do.
[00:45:36] John: Right! Well, it just happens. You know, I mean, we use things, we drop things, you know, as we’re going across the landscape, and I mean, not to get too far afield, but there is, there is the possibility that, you know, they’re out there just playing around. But that’s highly unlikely that all of these deposits would be from people just taking a leisurely stroll across the mud flats.
Again, hunter gatherers are living hand to mouth. It can be a hard way to live. You’re in a survival game all the time. And so, they’d probably be out there with a purpose. They’d be out there to collect seasonal resources or, you know, for some kind of purpose like that. And if they’re doing that, then they’re making tools, maintaining tools.
And so, you would see some kind of trace. And even if they’re using organic tools, which is, you know, it’s possible, totally possible, they’re still making those organic tools with stone tools and other kinds of materials. And so, you’d see the byproducts of that somewhere, you know, somewhere out there.
There would be the evidence for this, and maybe, you know, not even in the, the footprint area. But in 2014, 2015, you know, we did geological studies on the west side and we found buried surfaces that, you know, date to other time periods. So, there are other areas that you could, you could explore for these kinds of things as well.
But no, that’s a very legitimate thing.
[00:46:58] David: All I know is if you put me into a time machine, you dropped me out there 21- to 23,000 years ago, I’d be freaked out. I mean, that would be a very, very dangerous environment to be running around in. And you would stay away from the lake margin as much as possible because that’s where the predators are gonna be. It would be scary. It really would be scary. So, I don’t know. Who knows?
[00:47:23] Emily: One last really quick question. Is the nature of this debate in these two different camps that are dating the footprints differently, is it motivating both camps to keep looking and researching to try to come up with a more certain answer about how old these tracks are?
[00:47:42] David: The “Rebel Alliance” feels that way (everyone laughs). Uh, I don’t know about the Empire! So, uh, we’ve proposed things. We recently published a paper in PaleoAmerica, came out like a couple days ago, you know, bring up a lot of these issues and even new issues.
And, you know, when you bring up something, I feel like it’s a scientist’s responsibility to try to address something. And we got a response back and, you know, I, I didn’t get that impression. You know, we’re right. And you constantly have to keep checking yourself and you constantly have to be looking at your data in different ways.
And, you know, I could be totally wrong. I mean, I could be, but I, I do think I have enough evidence to indicate that the plant washed into the site, and if that’s the case, they didn’t fix the hard water effect. It’s a context issue, but there’ll be more to come. This isn’t going away. And I would say to the listeners, you know, before you jump on one, before you go with the Empire or you sign on board with the Rebel Alliance, give it ten years or so to let the dust settle and make your mind up then, because we’re only just getting started.
[00:48:44] John: That’s the cool thing about this, is that yes, hopefully it will lead to more discoveries, more work. Fifteen years ago, we didn’t know that those footprints were there. Now we do. Yeah. And so who knows what else might turn up?
[00:48:55] David: There’s value to the outrageous geologic hypothesis. There’s value to the outrageous archeological hypothesis ‘cause all it’s gonna do is more people are gonna invest more money, more time, and we’re going to really understand that basin in all its processes in leaps and bounds. Prior to that, it’s just a dead zone. And now there’s a lot of interest from a lot of people, and that’s a good thing. I think we need to think about that. I mean, it’s a positive, so…
[00:49:18] John: Yeah.
[00:49:19] David: And arguing about it, it’s not to be mean or, you know, or anything like that. It’s a part of the process, you know?
[00:49:25] Emily: Yeah. No, it’s exciting! (Everyone laughs)
[00:49:30] David: But at the end of the day, it is, it is a significant finding, and we just need to kind of fine tune that chronology a bit and see where it shakes out. I mean, put up a building around it. I mean, it needs to be protected and people should be able to see it. It’s pretty remarkable.
[00:49:43] Emily: So, yeah, well, thank you both so much for being here and having this conversation with me.
[00:49:48] John: Thank you so much for having us.
(Music continues, then fades)
[00:49:53] Emily: Now that you are thoroughly steeped in the details of carbon dating Ruppia seed balls, the hard water effect lake movement, and more, where do you fall in the White Sands footprint debate? If you want to join me down the rabbit hole of White Sands footprint research, check out the links in our show notes.
Thanks for listening.
(Music continues, then switches to outro)
[00:50:26] Emily: Encounter Culture is a production of the New Mexico Department of Cultural Affairs.
Our producer is Andrea Klunder at The Creative Impostor Studios.
This season is produced and edited by Andrea Klunder and Alex Riegler with additional editing by Monica Braine.
Our recording engineers are Collin Ungerleider and Kabby at Kabby Sound Studios in Santa Fe.
Technical direction and post-production audio: by Edwin R. Ruiz.
Our executive producer is Daniel Zillmann.
Thank you to New Mexico artist “El Brujo” D’Santi Nava for our theme music.
For a full transcript and show notes, visit podcast.nmculture.org or click the link in the episode description in your listening app.
I’m your host, Emily Withnall.
The New Mexico Department of Cultural Affairs is your guide to the state’s entire family of museums, historic sites, and cultural institutions. From Native treasures to space exploration, world-class folk art to ancient dinosaurs, our favorite way to fully explore is with the New Mexico CulturePass. To see everywhere CulturePass is accepted and reserve yours today, visit nmculture.org/visit/culturepass.
And if you love New Mexico, you’ll love El Palacio magazine. Subscribe at elpalacio.org.
Thank you for listening, and if you learned something new, send this episode to a friend or share it on social media. We love celebrating the cultures of New Mexico together.
[Theme music fades out]