Analysis and Dating of the Great Gallery Tool and Food Bag

By Phil R. Geib and and Michael R. Robins
Navajo Nation Archaeology Department

An image of a leather bag and three leather pouches
The Great Gallery bag shortly after recovery (left) and the leather pouches within the upper part of the bag (right).

Discovery and Location

In 2005, visitors to the Great Gallery discovered a leather bag eroding from eolian sand. The Great Gallery lies in Horseshoe Canyon west of the confluence of the Green and Colorado Rivers, and features large anthropomorphic pictographs that have a ghost-like quality. Based on similarities between the pictographs and clay figurines from nearby caves, some of this Barrier Canyon style rock art, as it is commonly known, is likely 7,000 years old, while some could have been painted as recently as 2,000 years ago. Fearing unlawful removal of the bag, a park ranger recovered the item on the day of its discovery. We obtained the bag and its contents on loan from the National Park Service to conduct the analysis reported here.

General Description

The above photo shows the overall bag as it appeared shortly after removal from the ground. The bag, which measures about 28 cm long and 8-10 cm in diameter, rests upon seeds that had spilled from the lower portion through a fresh rent. The bag had been separated into two compartments by wrapping the middle with a leather strap. Prior to being wrapped, the bottom of the bag had been filled with marsh-elder seeds, the volume of which was roughly the size of a softball.

After wrapping the middle part to secure the seeds, three small leather pouches and a small, water-rounded stone were placed within the upper part. These pouches are partially visible through the older, weathered rent in the hide. Two pouches were empty, but the third contained 40 chipped stone flakes, a biface, and a pressure-flaking tool of shaped antler. The mouth of the bag had been secured the same way as the middle part, by wrapping it with a leather strip. The bag and all pouches appear to be made of antelope hide.

The bag contains a softball-sized cache of marsh-elder (Iva xanthifolia) seeds weighing 193 g. Marsh-elder thrives in moist soils, often in disturbed farmland, but does not grow in the local area today. Although the leaves of Iva sp. have medicinal properties (Wyman and Harris 1951:48; Moerman 1988:279), its bitter and pungent tasting seeds were consumed as food by southwestern people as far back as the early Archaic (Hansen 1994:66), and are occasionally found in Formative period samples (Kirkpatrick and Ford 1977:262; Hammett 1993:Table 71). As we noted from modern plants, the quantity of seeds recovered from the cache can be gathered and winnowed very quickly. In less than five minutes, a single plant can provide a quick nutritious meal. We harvested a comparative sample in October, and seeds were observed in less plentiful quantities as late as December. Trace amounts of dropseed (Sporobolus sp. ), goosefoot (Chenopoduim sp.), and amaranth (Amaranthus sp.) were also noted in the cache, reflecting the use of this bag as a container for previous meals.

Dating the Bag

For radiocarbon dating, we obtained three tiny samples from different components of the cache:

  1. leather from the outer bag;
  2. a piece of the string tie of the interior pouch that held the flakes;
  3. some of the seeds that filled the bottom portion of the bag.

Barring the recycling of an old artifact or use of an heirloom, all three samples should be contemporaneous; indeed, this turned out to be the case. In conventional radiocarbon years the dates are no more than 60 years apart, with almost complete overlap of the calibrated two-sigma date ranges. The average of these three statistically identical dates is 1155±22 BP, which has a calibrated date range of AD 770-970.

an image of a tanned bag with cord stitched in it
Repair of an old rip in the bag

The Outer Bag

The outer bag was fabricated from a rectangular piece of tanned antelope hide with the hair removed. The grain or hair side of the animal is on the bag interior. The piece of leather was folded in half along its length, which measured about 28 cm. The folded portions were made flush along the side and an end, and the two layers were sewn together with sZ2 bast cordage using a simple running stitch, thereby producing a rectangular bag. At this stage the entire construction was pulled outside in so that the stitched seam was on the interior. Doing so drew the stitching tight and made the seam pucker slightly, producing a wavy appearance. The overall bag probably measured about 28 cm long by 12 cm wide, but exact measurements are not possible because of the leather strips that bind the center and open end. The bag had been repaired in several places to fix linear rents by using a simple wrapping stitch of bast or sinew cordage (all sZ2). A hole toward the opening was patched with a small rectangular leather scrap sewn to the bag interior with a simple running stitch and by being incorporated into the bag seam stitch (thus, the hole was repaired before finishing the bag).

Used Pebble

Loose within the upper part of the bag, underneath the three skin pouches, was a small water-worn pebble that exhibits use-wear. This oval, flat, dense igneous rock measures 75 x 42 x 19 mm. Both faces toward one end exhibit a worn area where randomly oriented fine striations and abrasion have removed the natural patina, exposing the natural lighter color of the stone. These wear traces are just the sort that we would expect from using the pebble to abrade the edges of flake blanks during flintknapping (platform preparation). Some slight pitting from hammerstone use is evident on the edge of the end opposite that with the facial abrasion.

The Pouches

Two of the three pouches from the bag are similar in construction, whereas the third is distinctive. The latter was made from an unsplit (cased out) leg section of hide from an antelope; conical in shape, only one end had to be sewn shut to form a bag, in this case the wider proximal portion, leaving the narrower distal part as the mouth. The bottom was secured by a running stitch using sZ2 sinew cordage, but unlike the other examples, this one wasn’t turned outside-in, so the stitching is exposed. This bag was empty and the leather unstained. It measures 11.5 cm wide at bottom, 5.5 cm wide at top, and 10.5 cm high.

The two pouches with a “flap type” of closure were constructed by starting with a rectangular piece of leather. Roughly 1/3 of an end was folded and overlain upon the middle 1/3; then the aligned edges on both sides were sewn together with a simple running stitch using cordage (sZ2 sinew for one, sZ2 bast for the other). This created a small bag with the remaining 1/3 of the length as a projecting flap. The construction was then pulled outside-in, so that the stitched seam was on the interior, making for a neat, finished look. A zS2 bast string was added to the flap so that it could be wrapped around the pouch and then tied to secure any contents. The leather for both of these pouches when dry had been purposefully stained red by hematite; the interior of the empty example was so darkly stained that it probably held pieces of this ore at one time. Flakes and a shaped antler pressure flaker filled the other flap type pouch. This full one measures about 9 cm wide, 7.4 cm high, and 3.5 cm thick with contents; the flat empty example measures about 9.5 cm wide and 8 cm high.

an image of two sides of a flat stone
Unfinished biface

Unfinished Biface

Included in the pouch with the flakes was a small unfinished ovate biface of Dubinky chert, the material that accounted for all but 2 of 40 flake blanks. The biface had been made on a thin flat flake, identical to those in the pouch, because both ventral and dorsal surface attributes were still visible. This biface measures 31.5 mm long (which is also the original flake length), 20 mm wide, and 4 mm thick (also original flake thickness). Most retouch occurred on the ventral surface and was focused on the bulbar swelling, with the distal third of this surface left unmodified. The invasive flake scars efficiently thinned the proximal twothirds of the blank; despite this, the platform surface remains partially intact. The flake scars are moderately broad for pressure, but this is what we would expect if using an antler bit like that included in the pouch. Pressure retouch on the dorsal surface is less extensive and invasive, mostly occurring along the proximal half of one margin. The ultimate tool form cannot be determined, but an arrow point certainly seems probable given thinness and lack of longitudinal curvature (section symmetry).

three angles of a brown tool
Antler pressure-flaking tool

Antler Flaking Tool

One of the more interesting finds in the bag is the flaking tool, shown above as it was first revealed upon opening the interior small hide pouch. This tool is similar in morphology to flaking tools made of mountain sheep horn that have come from Basketmaker II contexts of the Four-Corners region (Geib 2002). Some of the best examples of these occur together inside a dog bag cached at Sand Dune Cave and dated to the first few centuries AD (Geib 2004). The tool from the Great Gallery bag exhibits attrition to the ends from having been used to flake stone, but SEM examination did not reveal any embedded silica fragments. The small antler flaker measures 42 mm long, 13.5 mm wide, and 8 mm thick; at this size it would have been hafted to a stick for use as a composite pressure flaker like an example recovered from the Rasmussen Cave in Nine Mile Canyon, Utah (see Geib 2002:Figure 18.7). This flaker was probable put in the pouch because, in an emergency, 40 flakes blanks are worth little without the means for transforming them into useful tools--the two formed part of toolkit replacement parts that were essential to survival.

Flake Blanks

The 40 flakes from the pouch are interesting for several reasons: First, all but two of the flakes are of Dubinky chert, a distinctive cream and pinkish mottled silica that occurs as a lag deposit on the opposite side of the Green River. This is a linear distance of some 40 km as the crow flies, plus a few thousand meters of elevation loss and gain because of having to cross Labyrinth Canyon on the lower Green. Second, the flakes had been culled from the surface, presumably selected because they had desirable plan and section attributes. The flakes were differentially patinated, polished, and edge rounded from variable durations of surface exposure in the desert, but also exhibited more recent random nicks on the margins, perhaps largely as a result of bag transport in prehistory. Third, the flat and thin section of virtually all flakes suggests selection for facially thinned tool forms such as bifaces.

Moreover, the overall small size of the flakes is consistent with producing bifacial tools the size of arrow points. Based on this, we predicted that the radiocarbon dates would fall within the first millennium AD, after the introduction of the bow-and-arrow, which is indeed the case. The average size of Rose Springs Corner-notched arrow points from the nearby Cowboy Cave is 25.3 ± 4 mm (length) by 11.3 ± 0.8 mm (width) (Holmer 1980:Table 5). The average size of the 41 flakes from the bag is 31.5 ± 2.3 mm by 24.1 ± 0.5 mm, so well suited to the production of this arrow point.


Finds like the Great Gallery bag are remarkable because they are a literal time capsule, a rare glimpse into the personal effects of an individual from the distant past—the objects that sustained them, amused them, cured them; the valued objects that they made or found. Such finds allow exploration of prehistory in a personal way, a touching of part of an individual’s life story. Yet such finds can also inform on a much broader level, for the concerns of an individual reflected in their cached personal effects also reflect the concerns of the culture that the person was raised within and the behavioral strategies that helped to ensure survival. Because each cache pertains to only a segment of past reality, informing at this more general level requires compiling a composite image from the details and insights gleaned from numerous contemporaneous caches. Such a compilation must await future studies of bags like that reported here.

Our interpretation is that the Great Gallery bag was the possession of a flintknapper and hunter, one who had ventured across the Green River to the Dubinky chert source. He may have been on a hunt, but while there he scavenged surface flakes well suited to arrow point production. He collected more than needed for the short term, allowing 40 flake blanks to be cached. These he placed in a red-stained pouch along with an antler pressure flaker and an unfinished arrow point. Home was to the southwest, perhaps along the Fremont River, and the trip back brought him up Horseshoe Canyon—a natural travel corridor when heading southwestward out of the deeply entrenched Green River gorge. This led directly past the Great Gallery, a sacred place well known to the hunters of his group, so an excellent location for a cache, one easily remembered and described to kin. His travel bag for food was now almost empty but contained enough seeds to aid someone in dire need. The seeds were sequestered in the bottom by binding the middle of the bag with a handy leather strap. The flake-filled pouch with antler flaker was added to the upper part of the bag along with a worn out pouch that would make a handy palm pad when pressure flaking, and a small stone useful for edge abrasion and percussion flaking.

In the pursuit of game, hunters must commonly travel great distances, so mobility is simply part and parcel of protein acquisition. The caching of tools and emergency rations makes good sense in terms of costs and benefits, especially in a landscape where dry hiding places abound and are easily relocated and where geologic features constrain the movements of people. A cache like the Great Galley bag could save precious hours during a hunt by eliminating the need to search for raw material after breaking the last point. The handful of seeds could stave off hunger or even be the difference between life and death in the direst of circumstances. These benefits far outweigh the cost of leaving behind the bag, pouches, and other contents, even if, as happened in this case, the bag is never recovered. The few forgotten caches of prehistory likely represent just a fraction of the hundreds or thousands that were retrieved, and that doubtless provided the margin of survival in several cases and a huge relief often.


First, we would like to recognize the visitors, who discovered the bag and then responsibly notified the Park Service without removing the find. Because of their selflessness the Public has gained; everyone can enjoy both the objects and the insights to the past that they provide. Second, we thank Chris Goetze, Cultural Resource Program Manager, Southeast Utah Group, National Park Service, for bringing the bag to our attention and facilitating the artifact loan so that we could conduct this analysis. Tim Jull and the NSF-Arizona AMS Facility generously provided the AMS dates for our three samples. Ian Thompson helped with the identification of the hide and provided other useful information about tanning and leather preparation. Randy Haas confirmed the bast identification for the one cordage sample that we sent him. Greg Nunn first recognized the flake blank raw material as Dubinky chert and provided information about this source. Marilee Sellers of Northern Arizona University was of great assistance as usual with the scanning electron microscope. It was a pleasure to visit the Great Gallery this winter to examine the find location accompanied by Chuck Larue, a veritable fount of knowledge about local wildlife. We also extend a note of thanks to Phyllis Hogan and Karen Adams who provided useful information about marsh-elder.

Canyonlands National Park

Last updated: September 8, 2017