The Ancient Art of Stone Tool Bison Hides

Bison hide tanning is a deep traditional art. It was practiced by Native American ancestors at the end of the last Ice Age, and the skill has been passed down and perfected through the hundreds of generations since then. Indigenous communities spanning from Florida to Washington state and from central Canada to northern Mexico tanned bison robes at times when climate and other factors brought these giant, woolly creatures into their ares. Bison robe tanning is part of the heritage of many Tribal communities, yet while not a lost art, few people practice it today.

This post is the second in a series of three. The first shared the journey of braintanning the first bison robe from Nan Awaya Farm. The post you are reading now documents using stone tools to process two bison hides from the farm into a form ready to be tanned into robes. The third post, a how-to, will lay out the steps that I use to braintan a prepared bison hide into a soft, warm, wonderful-smelling robe.

These posts contain a lot of information. I hope that they may be of interest to our readers (most of whom are not hide-tanners), by bringing to light some of the knowledge and craftsmanship that are part of this little-known traditional art. I hope that these posts will contribute to the online resources available for people who want to learn how to do traditional bison hide tanning. Finally, with my training in archaeology, I know that most experimental studies in hidework are focused projects involving rote tasks on small pieces of hide. Maybe this account of processing two full bison hides with stone tools will be of use to some budding scholar out there.

For those who may be new to this blog, its perspective is from Choctaw traditional culture. The Choctaw homeland is present-day western Alabama and much of Mississippi. Choctaw ancestors interacted with the bison at the end of the last Ice Age, again when the herds moved into Choctaw country ca 1600-1740, and finally in Indian Territory after the Trail of Tears. In the Choctaw language, the bison is yvnnvsh, and the hide is called yvnnvsh hakshup.

The ancient art of bison-robe tanning begins with the selection of the animal. Prime wool is particularly important in southern climates. Bison wool reaches its prime between December 15 and January 15. Hides from animals harvested before December 15 will have less wool. Hides from animals harvested after January 15 may already be starting to shed (Bison lose their wool coat during the spring in preparation for summer heat). The window for prime bison robes overlaps with the hunting seasons of most Tribes, including the Choctaw owachito, or "big hunt". At this season, animals will have caloric reserves for winter (good eating), while the coolness of the weather makes it easier to process animal products without them spoiling.

Returning to animal selection, female bison have thinner skins (easier for the traditional tanner to process) and softer wool than do males. A 2-year-old female is an ideal choice for making a robe. A fine robe can also be made from older females and from bulls as old as 3, with more work. Latitude is also a factor, although not one that people of the past had much control over. For example, in the early 1700s, Choctaw people living in central Mississippi tanned wool-on bison robes, while their relatives living to the south on Mobile Bay tanned robes without the wool because the animals living in that hot, humid area had perennially thin wool. Similarly, a bison living in North Dakota today will have thicker wool and be larger size than a bison of the same age living in say, southeastern Oklahoma.

This year at Nan Awaya Farm, we processed two bison from our herd into meat for customers, a 2-year-old bull harvested in November and a 5-year-old cow harvested in early February. The 2-year old bull, "Spike", had been wreaking havoc on the farm for months, breaking down fences in order to exit pastures with good forage in hopes of finding something better somewhere else. We were concerned he might lead the herd off the farm some day. His meat went to the Choctaw Cultural Center, where he was served as the weekly special at least once. We kept and processed the hides of both of these animals.

In the Choctaw language, the process of skinning an animal is hluffi. I have twice recently had the privilege of studying a world-class collection of 18th century hide robes from North America for my day job. Clearly, for the different Native communities that made the robes in this collection, skinning was an artform. They used several different techniques, but all of them produced hides that were as close as possible to being rectangular in shape. Very few of the hides had any knife marks from cutting the hide away from the flesh.

Most modern butchers remove the hides from bison (or for that matter deer), using skinning incisions that run up the abdomen and meet incisions made up the insides of the legs. This creates a hide with an hourglass shape. That shape is not seen in old hidework. Most modern butchers further damage the hide by slicing score marks into it as they cut the hide off of the carcass.

Our butcher is a patient man, who lets Amy and me be hands-on in skinning our animals for robes. This year, we skinned our two bison by making an incision up the abdomen. A second incision was made from the top side of the knee on the front limb to meet the abdominal incision at the base of the neck. Then, we cut up the back side of the back legs. We each used a beveled hickory rod tool (isht bihli in the Choctaw language) and a fleshing tool made from a bison leg bone (see below), to separate the hide from the meat. Bison bulls and older bison cows have a lot of connective tissue holding the skin to what lies underneath. We worked in bands, using the wooden and bone tools to separate the hide from the meat for a couple of inches, then using a knife to cut the stubborn, remaining connections. We repeated again and again, all the way from the tail to the nose.

The hide must be processed quickly, before bacterial action causes the wool to start falling out. Once a hide is dry, bacterial action stops, and you can take a breather. Both times after butchering, we put the hides on a hide frame (isht tikili in the Choctaw language) the next day. Our frame measures 10ft x 10ft and is made of 2x6 boards. We cut inch-long slits about every 8 inches along the edge of the hide and used 12ft ropes to lace the hide to the frame. Care must be taken to stretch the hide evenly, as the shape of the finished robe is influenced by the way the hide is stretched on the frame.

Once in the frame, the next step is to flesh the hide, removing any fat, meat, or membrane that may still be adhering. The traditional skinning practice doesn't leave big hunks of meat on a hide, but bison have thick, hard fat on the hump and thick membrane containing small pieces of meat that need to be removed for the hide to dry. Even where the membrane is thin, like cellophane wrap, it must be removed in order for the dressing solution to penetrate to allow the hide to soften the hide in later steps. A common tool that was used in the past was a toothed flesher, made from a bison cannon bone (lower back leg). The lower end of the bone is cut off at a 30 degree angle, and small teeth are filed into it. Attaching a buckskin strap, made to wrap around the wrist, makes the tool much easier to work with. Used in a downward, stabbing motion, the flesher's teeth grab onto the membrane and fat to help peal them away from the hide. The bone is not sharp enough to cause any damage to the hide itself. I fleshed half of the bull hide and 100% of the cow hide using this tool.

After fleshing, the hide can dry. It will become dark-colored as it dries. At this point, it cannot be allowed to sit flesh-side towards the sun for very long, because the dark-colored hide will absorb enough heat to grease burn, ruining it. In our humid climate and with our work schedules, it's most practical to leave the fleshed hide on the frame in the shop and put two fans and a dehumidifier on it. The biggest part of a bison hide will dry in a day. The mane on the neck usually takes 4 days.

In order for a bison hide to be tanned into a wool-on robe, not only does it need to be fleshed, but it must also be thinned. Portions of bison hides can easily be 1/2 inch or more in thickness. Every portion of the hide needs to be thinned down to the thickness equivalent to about two sheets of construction paper. Proper thinning is one of the two main keys to successfully producing a traditional buffalo robe. The primary tools used to thin bison hides in the past were stone-bladed hide scrapers.

Scrapers made from flint-like stone are ubiquitous on archaeological sites. Not everything that people, including archaeologists, call a hide scraper was really used for this function. The scrapers that really were used to thin bison hides were almost always made on a long, narrow flake of stone by chipping the distal end into a sharp, rounded, and very even cutting edge. Evenness of the edge is important. Burs, even 1/16 of an inch on the scraper's cutting edge will leave score makes in the hide. Scores made into the hide during skinning or during the process of thinning a hide grow in size later during the process of softening the hide. Severe scores create weak places that can rip out catastrophically. Of all of the scrapers I've seen in the archaeological collections, one in particular stands out. It was made by a Native person living in Old Mobile in the early 1700s. It was chipped from a thick piece of olive green glass, obtained from the French (see photo). From shape, location, and time period, this scraper may very well have been made by a Choctaw-speaking person to process bison hides.

To process our two hides, I made my scraper blade out of a long, narrow flake of Edwards Plateau chert. I wrapped it onto an elk antler scraper handle (title image) that I had made long ago, and went to work.

Properly thinning the hide requires both heavy work and precision. Thinning the neck on a bull can require removing 7/8 of this tough hide's thickness, but scrape 1/16 of an inch too deep, and you'll create a weak place in the hide that can rip during softening. My preference is to use a sharp flake of stone or a thin knife to carefully fillet most of the neck thickness away. The animal's mane runs through the center of the hump and must be thinned significantly, but the surrounding hump skin is quite thin. Dealing with the transition is more difficult because the dish-shaped nature of the hump makes it hard to bring tool edges to bare in the needed spots. The area along the spine is thick and must be thinned a lot. In the past, hides were often processed by cutting them in two pieces, lengthwise. When this was done, a strip of hide including the mane and spine was discarded to make tanning easier (resulting in the loss of the tail). After softening, the two pieces were sewn back together. The hips must also be thinned, particularly on cows. The elbow areas near the front leg have a thick membrane, but the hide is thin and doesn't stretch. This is a recipe for punching holes during thinning. The legs also have a thick membrane and thin skin, but are relatively easy to soften. The tail has a thick membrane, and can be softened into pliability, but never really becomes soft. Other areas of the hide can be thin, particularly on a cow.

As the hide is thinned, it becomes easier for its coarse fibers to stretch, turning the hide white. This whitening is a first sign that thinning is on the right track. Soon, you can start to feel the hide stretching under the scraper with each pass. At this point, I start reaching around the edges of the hide, to feel its thickness between my hands. Soon, I unlace portions of the hide from the frame and see how the middle responds to rolling and bending. I've found that a sufficiently thinned hide will bend about as easily, if not more easily, than a single thickness of cereal box cardboard. If it's any stiffer than that, more thinning is needed. If certain spots are more resistant to bending than the areas immediately around them, I concentrate on the resistant spots. If a portion of the hide is too thin to use the scraper on, but still retains membrane, it can be sanded with a rounded piece of sandstone, or 60 grit sandpaper. Again, I can't stress enough how important thinning is for not killing yourself later in the softening process and for ultimately ending up with a soft robe.

I thinned both of these hides using nothing but the stone-bladed scraper. This was the first time I've used a stone scraper for thinning bison, and I found that I liked it better for the purpose than the metal tool that I had been using. The edge of the stone is much easier to keep at the proper sharpness, at least for me. When it started to get dull, I could rechip the edge with an antler tine pressure flaker in a minute or less. I used the new, sharp edge to work on the thinnest areas of the hide, and as the edge started to get duller and require a little more force, I'd move to a thicker area of the hide where there was less danger of punching through. I punched through several times on the bull, and then only once on the cow hide. Minor burs in the scraper's stone edge are a fact of life. These were an advantage in plowing away unwanted thickness on the thicker areas of the hide, but they do leave score marks in the hide. Several of the scores I made would later rip out during thinning, but after sewing the holes up with sinew, the rips can no longer be seen (see next post).

The patterns left by the stone blade were interesting. It's no surprise that the stone's rougher edge left a hide with a rougher surface than one processed using a metal scraper (see image). I did find that I could produce a scraper blade edge that left no score marks by resharpening it using a horizontal antler beam punch. The resultant edge, although effective at first, only kept its sharpness for about 20 passes. That is pretty wasteful of stone, so I went back to the pressure flaker. In the fine-textured areas of the hide, most traces of the scraper's burrs would ultimately get obliterated during the softening process. On the courser-grained areas, fine, even ridges left by the scraper would be a permanent feature of the finished robe.

The last time I had used a stone scraper on a bison hide, it was simply to remove the hair, rather than thinning away almost the whole hide to make a robe. Made of crumbly, raw, Harvester chert, that scraper blade worked, but had to be constantly resharpened. The raw Edwards chert, both fine grained and tough, kept its edge well. I resharpened it probably 100 times, but it lasted to completely thin both of the bison hides. That was a level of durability that I had not expected. Here are three views of it after the work on both hides was complete. I wish that I had measured it at the beginning, to see how much length of the scraper got used up in doing the two hides. Since I thought I would be using up a number of scraper blades, I didn't. However, I plan to continue to use stone scrapers processing bison hides moving forward.

Once a bison hide is thinned, it can be stored in a safe place. The thinned hide, with the wool on is especially vulnerable to damage from hide-eating insects and as well as rain. Hanging it in the smokey eaves of a traditional building would be a good place, or it can be processed into a robe immediately. Stay tuned for the next post in the series, which will lay out the steps that I am currently using to tan bison robes traditionally.