An article in the journal Science provides new research that Indigenous people were using horses in the American West much earlier than previously thought. The research has major contributions from a University of Wyoming (UW) graduate’s own research. Cassidee Thornhill earned her bachelor’s and master’s degrees in anthropology from UW. Wyoming Public Radio’s Kamila Kudelska spoke with Thornhill about her research.
Editor’s note: This interview has been lightly edited for clarity.
Kamila Kudelska: What’s the story that we knew about Indigenous people and horses?
Cassidee Thornhill: Well, we knew that with the introduction of horses into Indigenous lifeways that it certainly changed day-to-day lifeways and distances that could be traveled [and] warfare. It changed a lot of aspects of Native lifeways. We knew that a lot of Plains tribes in particular, really found [a] strong identity with being a horse nation. What we know of how the relationship began, though, is mostly due to historic writings and recordings, which of course, is kind of one-sided. It's only from the viewpoint of Euro-Americans.
KK: What type of research did you carry out?
CT: When I started getting into it, I talked to Danny Walker, he's a zoo archaeologist. He was the assistant state archaeologist. And he actually did the original analysis of the Blacks Fork River horse, and he was able to point me to that horse in particular. At the time, the only other known horse from this time period that was definitely not Euro-American, which is right outside of Casper, is just a skull fragment. And just knowing that there were only two in all of Wyoming from this time period, and needed greater investigation, I think.
KK: So how did you go about that?
CT: Well, I decided that the Blacks Fork River horse was a really good example that could use re-analysis and further analysis of the remains because it's so complete. Like I said, the one in Casper is just a skull fragment, it's just the base of the skull. That doesn't really give us a whole lot to work with. And this happens to be the case with a lot of horses throughout the Plains.
I wanted to re-establish the age of the horse, which is five to six months, which is pretty close to what they had originally determined in the first analysis. I decided to look at the human modifications, the cut and chop marks a little more closely, because fortunately, some other people in the department were doing research on identifying stone versus metal cut marks. So I wanted to apply that research to this, specifically.
And then I think most importantly, was re-submitting some radiocarbon dates because the initial dates they did too, and one of them came back just so broad that it didn't really give us a very good idea of when this horse had died. And then the other date just came back simply as modern, which also isn't very helpful for our understanding of when the horse had died. I thought that was probably the most important thing that can be re-contributed was to attempt to re-create it with more current methods.
KK: What did your results show?
CT: There were a lot of cut and chop marks, mostly chalk marks throughout, a lot of the skeleton on the vertebra, on the ribs, on the femurs. But these cut and chop marks are not very similar to those that we usually see on other animals and horses in other parts of the world that are being consumed for food. It looks like this horse was partially disarticulated, and then placed with little to no evidence of any kind of de-fleshing or skinning or anything that would indicate that it was being used in some way, other than just the potential that it was just ritually buried. It had also been buried with three coyote skulls.
I was able to determine that all of the cut marks and chop marks were made by metal tools, which is important because no other artifacts were found with it. No chipped stone artifacts, certainly no metal artifacts, and just like how the horses are quite early from what we would normally expect. Metal tools are quite early as well for being in Wyoming at that time.
The date came back as a medium date of 1640, which is a little early. [It was] originally thought that horses arrived in Wyoming about 1700, and that's based off of rock art, which is notoriously difficult to date, and of course, also what we could get from the historic records and oral stories. But 1640 is a little bit early but not outlandishly early, but it does place the timeline a little bit earlier, which is significant because in the original narrative of how horses spread throughout the Plains, it was thought that horses couldn't have escaped from the Spanish before 1680, which is when the Pueblo Revolt occurred in New Mexico. The original thinking was that the revolt happened, the Pueblo people were able to get access to these horses and then disseminate them further onto the Plains. But the 1640 date shows that they were probably being transmitted via Indigenous transmission, non-European transmission earlier than what we thought, adding more agency to Indigenous peoples.
KK: The paper that recently got published in Science adds more research on top of your research proving what you just mentioned. So can you explain how that extra research contributed to what you have found?
CT: The additional research in Science, they were able to comment more on some of the morphology on the skull. When I had done the analysis, I had noticed that there had been an injury to the horse's skull, but Will Taylor, who's the lead author on the Science article, he was able to look more in depth at that and see that it was almost healed, which might indicate veterinary care. So the horse was injured in some way, probably kicked by another horse and then it was at least cared for for a little while.
The research expands to several other horses. One of the other horses that gets a lot of discussion in the article is from Kansas. And it also dates to about the same time as the Black Forks horse. It shows evidence of the use of a metal bit. I think they did isotopic analysis on both the Kansas horse and the Black Forks horse. For the Kansas horse, they saw evidence that it was potentially being fed corn or maize, in addition to whatever else was in its diet, probably during the winter.
For the Black Forks horse, they were able to see that the isotopes matched other isotope levels for that specific area of Wyoming, so indicating that the horse probably was born and raised up until it was five or six months old, just in that small part of Wyoming and that its mother had probably been there for a little while. Both of these horses, plus some of the other evidence that is talked about in that article, show that the spread of horses, it's not a random occurrence. The Blacks Fork horse, it's the digital proof that yes, horses probably disseminated from the southwest prior to the Pueblo Revolt, and most likely by Indigenous people’s trade networks.
KK: Why is that significant?
CT: Well, I think it's significant because the original narrative doesn't really give a lot of credit to the way that horses spread and integrated so quickly to the Indigenous people. A lot of the early narrative is that they couldn't have gotten access to horses prior to this Pueblo Revolt, which is probably not true.
There are some records that some groups were probably raiding Pueblo people and Spanish people down in the southwest, and then they could have captured and brought horses further north with them and then through these trade networks dispersed them. I think that what is most significant is that a lot of the narratives so far has been very much one-sided towards Euro-American records. This just shows that the story is a lot more complicated than what we initially thought.
The Blacks Fork horse in particular shows evidence of specifically Comanche; ancestral Comanche people are Shoshone speaking and they are partially from that part of Wyoming. And initially, it was thought that they had moved south in order to get horses. But the Blacks Fork horse shows that that's probably incorrect, that they already had horses before they spread south and they used their equine knowledge and extreme skill with the horse to expand to a large area in the southern plains and create what was ultimately an empire, based off of horses and bison.
Update 5/1/23: The transcript was updated to reflect that it was previously thought that horses arrived in Wyoming in 1700 not 1600. The interviewee made a mistake during the interview.
