Agate Basin to Scottsbluff Along the SHADOWS on the TRAIL

Figure One - Development continuum of Paleoindian projectile point types. From left to right, 

oldest to youngest, Agate Basin, Hell Gap, Alberta, and Scottsbluff. All surface finds are from 

private land in Colorado. For scale, the Agate Basin point on the far left is 4.6 inches long. 

John Bradford Branney Collection.  

In my prehistoric adventure series the SHADOWS on the TRAIL PENTALOGY, three Paleoindian tribes clash on the high plains of Colorado. All three Paleoindian tribes lived similar lifestyles as hunters and gatherers but what differentiated them was their stone weapon tips. While the three tribes all used ‘old world’ spearthrower or atlatl technology, their stone projectile points varied in style and technology. Let me guide you on a short journey into the past. Everyone climb aboard my Delorean time machine. Our destination is southern Colorado about 12,600 years ago.  

Figure Two - Delorean time machine from Back to the Future.  

In the first book of the PENTALOGY titled SHADOWS on the TRAIL, warriors from a tribe of people I called the Mountain People brutally attack the village of a peaceful tribe called the River People. When the attack occurred, most River People men were not in the village, but on a hunting expedition. There were not enough spears to defend the village from the brutal onslaught of the Mountain People. The hunters returned and found the complete destruction of their village and the murder of friends and loved ones. The hunters wanted their revenge but they did not know who inflicted that deplorable act upon their people. The only evidence was a spear in the brush left behind by a warrior from the Mountain People. The spear's owner carved a clue for the hunters on the wooden shaft of the spear, and the stone projectile point at its tip was a different kind. The hunter who discovered the spear brought it to his leader, a man named Avonaco and this was what happened; Lights, camera, action:   

Avonaco held the spear in his hands. The spear shaft was the same wood that the River People used, but the stone spear point was different. The stone spear point was thinner and longer than any Avonaco had ever seen and made from a shiny, black rock material. Avonaco ran his thumb down the sharp edge of the spear point and quickly pulled his thumb away.

“Éŝkos!–Sharp!” Avonaco exclaimed, looking down at his bleeding thumb.

He continued to examine the spear point, “I have only seen a spear point like this once made from this black rock. When I was a boy, I found a spear point much like this deep in the mountains. My father told me the black rock comes from the mountains.”

Avonaco then inspected the sinew wrap that connected the stone spear point to the wooden spear shaft. The River People used sinew from deer or bison to attach their spear points.

Avonaco pointed to the sinew and said, “This is too thin, it is not from bison or deer.”

Avonaco ran his fingers down the smooth wood of the spear and noticed it had carvings in it. To see better, Avonaco moved the spear shaft closer to the light of the campfire. Carved into the wood were five green-painted peaks next to two orange-painted suns,   ҉   Ʌ Ʌ Ʌ Ʌ Ʌ   ҉. , Waquini and Vipponah leaned over Avonaco’s shoulders to take a better look.

I wonder if the River People ever got their revenge? If you want to find out, you are going to have to read the second edition of SHADOWS on the TRAIL. CLICK IMAGE BELOW for info on the BOOK. 

CLICK for the BOOK

Now, the rest of the story!

In figure one above, I photographed four different Paleoindian projectile point types, from left to right, the oldest to the youngest; Agate Basin, Hell Gap, Alberta, and Scottsbluff. The cultural adoption of these four projectile point types was widespread from Canada to Texas through much of the Great Plains and the southwestern United States.

We know from archaeological evidence that different Paleoindian cultures used different projectile point types. We know through investigations at single-episode bison kill sites that Paleoindian hunters often used the same projectile point styles. That suggests to me that the specific tribe or culture involved in each bison kill determined the projectile point style and technology used by the hunters who participated in the bison kills. A few examples of High Plains Paleoindian bison kill sites and the respective projectile point types in parentheses are Casper (Hell Gap), Olsen-Chubbuck (Firstview), Hudson-Meng (Alberta), Jimmy Allen (Jimmy Allen), and the Horner Site (Cody Complex). Either that means that everyone in the tribe was flintknapping to the same style of projectile points or perhaps, there were one or two expert flintknappers within the tribe making all the projectile points. 

Figure Three - Agate Basin projectile points and one drill. On some Agate Basin projectile points
the "Hell Gap shoulder" was already developing. For scale, the far left point is 2.2 inches long.
John Bradford Branney Collection.

Based on radiocarbon dating and geologic studies, Agate Basin is the oldest projectile point out of the four artifacts in figure one. Current archaeological evidence proposes that Agate Basin projectile points and knife forms showed up on the high plains around 10,400 years BP, or north of 12,000 years ago in calendar years. Based on radiocarbon dates and geologic studies, the Agate Basin projectile point could have overlapped in time with at least three other projectile point types; Folsom, Hell Gap, and Alberta. We know it overlapped in geographical space! 

Based on stratigraphic evidence at the multicultural Hell Gap site in Wyoming, investigators determined that the Hell Gap culture was younger than the Agate Basin culture, at least at the Hell Gap site. The age most often assigned to the Hell Gap prehistoric culture is around 10,000 years BP or around 11,500 years ago in calendar years. Based on projectile point technology, many investigators believe that Hell Gap projectile points evolved from Agate Basin projectile points. 

In experimental archaeology hunting exercises, Agate Basin proved to be a very effective piece of weaponry, so why did Paleoindians move from Agate Basin to Hell Gap projectile points? One possible explanation could be less time and effort exerted on making Hell Gap versus Agate Basin. If you have ever examined a well-made Agate Basin projectile point, it is obvious that a great amount of time and effort went into its making. In Agate Basin projectile points, fine pressure flaking was used to achieve exceptional point symmetry. Did that extra effort deliver incremental hunting performance? We will never know the answer to that question for sure. Some might call Agate Basin points "flint knapping overkill". The Hell Gap flint knapper usually terminated the finishing process of a projectile point much earlier than an Agate Basin flint knapper (figure four). The Hell Gap flint knapper oftentimes used only pressure flaking on the stems and tips, leaving a rougher and less symmetrical projectile point. And it appears that the Hell Gap shoulders that they introduced made for a better hafting arrangement.  

Figure Four - Hell Gap Projectile Points. The Hell Gap shoulder is fully developed 
on these examples. For scale, the far left point is 2.5 inches long. 
John Bradford Branney Collection. 

Over 11,000 calendar years ago near Casper, Wyoming, Paleoindian hunters used Hell Gap projectile points to kill bison that they stampeded and trapped in sand dunes at what we now call the Casper site. During a similar timeframe in Nebraska, a different group of Paleoindian hunters used what we call Alberta projectile points to dispatch bison they trapped in an ancient arroyo at the Hudson-Meng site. Dr. H. M. Wormington identified and named Alberta projectile points from surface recovered examples found during the dust bowl years of the 1930s in Alberta, Canada. The long stem and abrupt shoulders differentiated Alberta projectile points from both Agate Basin and Hell Gap. We assume that at least some Paleoindians felt the Alberta projectile point design was an advancement in weapon technology over Agate Basin and Hell Gap projectile point designs. When spearing a bison or other game animal, the shoulders and long base of the Alberta projectile point handled much more stress and impact, probably creating a more efficient weapon tip.    

The Alberta projectile point technology and style then gave birth to another projectile point type. The point to the far right in figure one is a Scottsbluff point, a continuation of Cody Complex weaponry and a point design originating from the earlier Alberta projectile points. 

Figure Four - Examples of Cody Complex artifacts, including  Alberta (far left) and 

Scottsbluff (third from left). For scale, the far left point is 2.5 inches long. 

John Bradford Branney Collection. 

The stem and shoulders found on Alberta points existed on Scottsbluff points but what returned was the fine pressure flaking and symmetry of the earlier Agate Basin projectile point.

So, what do you think drove the development continuum of Paleoindian projectile points from Agate Basin to Scottsbluff? Was it technological innovation or were different prehistoric cultures putting their own stamp on weaponry design? Why did Paleoindian cultures adapt the same projectile point type across a wide geographical area? Why did Paleoindians use a specific projectile point type at one bison kill while at a similar timeframe other Paleoindians used a different projectile point type at a different bison kill? Were different people making specific projectile point types? 

Food for thought! 

We can only hypothesize, but isn’t that fun to do?

CLICK for the Journey - SHADOWS on the TRAIL PENTALOGY

The historical fiction novels written by John Bradford Branney are known for their impeccable research and biting realism. In his latest blockbuster novel BEYOND the CAMPFIRE, Branney catapults his readers back into Prehistoric America where they reunite with some familiar faces from Branney’s best-selling prehistoric adventure series the SHADOWS on the TRAIL Pentalogy.

John Bradford Branney holds a geology degree from the University of Wyoming and an MBA from the University of Colorado. John lives in the Colorado mountains with his wife, Theresa. BEYOND the CAMPFIRE is the eleventh published book by Branney.

The Hell Gap Complex Along the SHADOWS on the TRAIL

Figure One - Flintknapping technology from Agate Basin to Hell Gap projectile points. 
The point on the far left is Agate Basin, while the other three points are Hell Gap. For  
 scale, the Agate Basin point is 2.45 inches long. John Bradford Branney Collection.   

In figure one, I photographed four high plains projectile points from my collection: on the far left is a 2.45-inch-long Agate Basin projectile point, and on the right are three Hell Gap projectile points. Bradley (1991:382) proposed that the manufacturing process for Hell Gap projectile points was an outgrowth of a well-developed Agate Basin projectile point technology. He postulated that the production sequence was the same for both projectile point types: first, there was percussion thinning and shaping, followed by pressure thinning and shaping. Bradley stated that the makers of Hell Gap projectile points just terminated their flintknapping process earlier than the makers of Agate Basin projectile points. 

Fortuitous circumstances led to the discovery of the Hell Gap archaeological site in southeastern Wyoming. Since its discovery over sixty-some years ago, Hell Gap has become one of the most important archaeological discoveries in North America and the type site for the Hell Gap projectile point. 

On May 22nd, 1958, James Duguid and his family were travelling north along a gravel road between Guernsey and Lusk, Wyoming, along the eastern flank of the Hartsville Uplift. Along came one of those afternoon rain showers that temporarily flooded a low spot in the road. The floodwaters forced the family to stop and allow the water on the road to drain. The family bided their time by walking and artifact hunting in the immediate area. Duguid discovered some interesting artifacts in an arroyo and promised himself that he would return the next day to finish the hunt (Duguid 2009:313-314).

Figure Two - A 2.55-inch-long Hell Gap projectile point/knife form surface found
on private land in Morgan County, Colorado, and made from a pretty
caramel-colored jasper. John Bradford Branney Collection. 

Duguid and a friend returned to the site the next day, and Duguid found a complete Agate Basin point along with a lot of flintkapping debris. He returned to the site with his father and another friend the very next day, on May 24th. Duguid's father, Otto, discovered what appeared to be a Paleoindian projectile point eroding from a cutbank. That point was later determined to be a Hell Gap projectile point. Between his father's Hell Gap point and his Agate Basin point, Duguid recognized that they stumbled upon a very special place. However, he was hesitant to report the site to professional archaeologists because he knew that there were archaeologists who failed to report and document other excavated Paleoindian sites in the area. Duguid was worried that the same fate might befall his newly discovered secret.   

Figure Three - The Hell Gap Paleoindian site
in the late 1960s.

In the fall of 1958, James Duguid began working on his geology degree at the University of Wyoming. In the fall of 1959, Duguid reported the site to University of Wyoming anthropology professor George A. Agogino. The professor convinced Duguid to take him to the site to investigate it. Duguid and his father escorted Agogino to Hell Gap Valley, and the rest was history, or in that case, prehistory. 

Sixty-plus years later, archaeologists are still investigating the Hell Gap Site. Hell Gap remains one of the most important archaeological discoveries in the Western United States during the past one hundred years, and that came about because of an avocational archaeologist named James Duguid. 

Figure Four - A mixed hand of Agate Basin and Hell Gap projectile points collected
from the High Plains. Which points are Agate Basin and which are Hell Gap?
My answer is found in the last paragraph of the article. 

George Agogino (1961) defined the Hell Gap projectile point type from examples found in Hell Gap Valley and the archaeological site. Hell Gap projectile points were medium to large lanceolate-shaped points that were similar to Agate Basin points, except that the Hell Gap projectile points bore shoulders. Hell Gap stems were long and contracting. The blade edges from tip to base were either straight-to-concave or convex-to-straight-to-concave. The basal edges of the points were often ground and polished, which gave investigators an indication as to how far up the projectile point was hafted. The basal corners ranged from sharp to ground and polished smooth. 

 

Figure Five - Two examples of Hell Gap projectile points (o and p) found
in situ with Agate Basin projectile points at the Agate Basin site in 
eastern Wyoming.  Frison and Stanford (1982:101)

Based on excavated bison kill sites, it appears that Hell Gap Paleoindians participated in large, well-organized communal hunts for meat acquisition, much like their Paleoindian predecessors. Figure five is a photograph of a few projectile points excavated in a bison bonebed at the Agate Basin site in eastern Wyoming (Frison and Stanford 1982:101). In that photograph, two of the projectile points (o and p) were classic Hell Gap projectile points with shouldering. Those Hell Gap points were excavated from the same bonebed and stratigraphic level as Agate Basin projectile points. In addition to those two Hell Gap points, there were other examples of Hell Gap points excavated from the Agate Basin bonebed, which provided evidence of a relationship between the two point types. Based on the evidence, it seems likely that Paleoindians used Hell Gap points contemporaneously with Agate Basin points at the Agate Basin site. 

Figure Six - Select Hell Gap sites from Stanford (1999:318)

Stanford (1999:318) published the map in figure six of important Hell Gap sites along the High Plains. He noted that the number of Hell Gap sites was less than Cody and Folsom sites for the same area. Stanford made no assumptions or conclusions as to why there were fewer Hell Gap sites. 

The Casper Site was originally discovered by avocational archaeologists. George Frison (1974) investigated the Casper Site in central Wyoming and determined it was a late-autumn bison kill site where Hell Gap Paleoindians harvested around one hundred animals by immobilizing them in the deep and shifting sands of a parabolic dune.  

Using several Hell Gap point specimens from the Casper Site, Bradley (2010:487) proposed a special bifacial reduction process. He noted that Hell Gap flintknappers achieved the general shape and regularity of the biface by serial percussion thinning on one side with a hammerstone. In the world of flintknapping, serial percussion thinning usually results in the arrises, i.e. the high ridges at the flake margins, trending in the same direction. The Hell Gap flintknappers skillfully controlled the spacing and the thinning flakes that crossed the surface of the biface. Many of the thinning flakes reached or almost reached the other edge of the biface. 

Figure Seven - Clovis point and three 
Hell Gap projectile points from the
Casper site (Frison 1974:74). 

The Hell Gap flintknappers then turned the bifaces over and percussion thinned from the opposite edge, creating bifaces with cross-sections resembling a parallelogram. After serial percussion thinning, the Hell Gap flintknapper shaped and straightened the margins of the biface using direct percussion with an antler or hammerstone or by selective pressure flaking. Hell Gap flintknappers used platform isolation and moderate-to-heavy grinding to prepare the striking platforms for percussion flaking. Unlike Clovis striking platforms, Hell Gap flintknappers used smaller and more convex-shaped striking platforms. Bradley found in his study of the Hell Gap projectile points from the Casper site that a few flintknappers used percussion flaking exclusively, while others chose to retouch the margin edges with pressure flakes, particularly near the tips and bases of the bifaces. Ultimately, the finished bifaces ended up with lens-shaped cross-sections. Figure seven represents the forms and flaking patterns of one Clovis and three Hell Gap projectile points found at the Casper Site.    

Cassells (1997:79) reported that in the summer of 1972, rancher Robert Jones Jr. uncovered bones and artifacts while levelling a ridge near his home near Wray, Colorado. Jones contacted a local anthropologist named Jack Miller, who conducted a few test excavations in the bonebed. Miller recognized the significance of the site and contacted archaeologist Dennis Stanford at the Smithsonian Institute. Full-scale excavations at the Jones-Miller site occurred between 1973 and 1978. 

Figure Eight - CLICK for SHADOWS on the TRAIL

The Jones-Miller investigations uncovered the bones of approximately three hundred bison in a shallow arroyo above the Arikeree River floodplain. Based on bison tooth eruption patterns, the investigators determined that the animals were most likely killed during three episodes over one or more winters. The projectile points that the investigators found were mostly of the Hell Gap variety. Taylor (2006:207) reported and photographed what appeared to be Agate Basin points found with the Hell Gap points from a single kill episode at Jones-Miller. That either meant that Agate Basin and Hell Gap hunters were cooperating at that bison kill, or the mixture of point types represented the same complex using two different styles of points. In my opinion, the situation at Jones-Miller was most likely the latter. 

Stanford (1999:316-318) observed that during the refurbishment or resharpening of Hell Gap points, the flintknappers could narrow the blade edge enough to make the points indistinguishable from Agate Basin points. Peck (2011:55) lumped Agate Basin and Hell Gap into the same archaeological complex based on the overlapping projectile point technology and the association between the two-point types at several archaeological sites such as Agate Basin, Carter-Kerr McGee, and Jones-Miller. Peck reported an age of ca. 10,500 to 10,000 BP for Agate Basin materials and an age of ca. 10,000 to 9,500 BP for Hell Gap materials at the Hell Gap Site in Wyoming (Irwin-Williams et al. 1973:52). To obtain the age of the materials in calendar years, the radiocarbon ages must be corrected.         

Based on the archaeological evidence at Jones-Miller, the investigators proposed that Paleoindians trapped the bison in a topographical trough. The investigators found evidence that the Paleoindians might have used an enclosure or corral around the trough. Since the bison harvest took place in the wintertime, the investigators hypothesized that the entrance leading into the trough might have been slick with snow and ice, making it difficult for the beasts to escape. The hunters then trapped and dispatched the beasts with spears and possibly spearthrowers. Jones-Miller remains the only excavated Hell Gap site in Colorado. 

Figure Nine - From left to right: Two Hell Gap projectile points and two Alberta 
projectile points from my collection. Note the shouldering on the Hell Gap
projectile points and the stemming on the Alberta projectile points.  

What happened to the Hell Gap projectile point technology?     

Figure nine is a photograph of four projectile points from my collection. These projectile points represent a plausible technological transition from the shouldering on the first two Hell Gap points on the left to the stemming on the two Alberta points from the Cody Complex on the right. The notion that Hell Gap projectile point technology evolved into Alberta projectile point technology is also supported from a temporal perspective. Kornfeld et. al. (2010:237) reported that the Alberta component at the Hudson Meng bison kill site in Nebraska was approximately the same age as the Hell Gap component at the Casper bison kill site in central Wyoming. Both sites were dated to around 10,000 years BP (uncorrected radiocarbon date). While Hell Gap hunters were trapping bison in a parabolic sand dune in Wyoming, Alberta hunters were trapping bison in an ancient arroyo in Nebraska.    

I hope you enjoyed the article. I am currently writing the sixth book in my SHADOWS on the TRAIL Hexalogy. Check out the series if you enjoy adventures about Paleoindians living on the High Plains.

Oh, I almost forgot about the projectile point types in figure four above. From left to right, the point types are Agate Basin, Hell Gap, Agate Basin, Hell Gap, and Agate Basin.     

Until next time, HAPPY TRAILS!  

References Cited.  

Agogino, George A. 1961. A New Point Type from Hell Gap Valley, Eastern Wyoming. American Antiquity 26: 558-560, Salt Lake City.  

Bradley, Bruce A. 1974. The Lithic Technology of the Casper Site Materials in The Casper Site: A Hell Gap Bison Kill on the High Plains, edited by George A. Frison. Academic Press. New York.   

Bradley, Bruce A. 2009. Bifacial Technology and Paleoindian Projectile Points in Hell Gap: A Stratified Paleoindian Campsite at the Edge of the Rockies, edited by Mary Lou Larson, Marcel Kornfeld, and George C. Frison. 

Bradley, Bruce A. 2010. Paleoindian Flaked Stone Technology on the Plains and in the Rockies in Prehistoric Hunter-Gatherers of the High Plains and Rockies. Third Edition. Edited by Marcel Kornfeld, George C. Frison, and Mary Lou Larson. Left Coast Press. Walnut Creek.      

Cassell, E. Steve. 1997. The Archaeology of Colorado. Revised Edition. Johnson Books. Boulder.   

Duguid, James O. 2009. A Paleoindian Site Discovery in Hell Gap: A Stratified Paleoindian Campsite at the Edge of the Rockies, edited by Mary Lou Larson, Marcel Kornfeld, and George C. Frison.    

Frison, George A. 1974. The Casper Site: A Hell Gap Bison Kill on the High Plains. Academic Press. New York.   

Frison, George C., and Dennis J. Stanford. 1982. The Agate Basin Site. Academic Press. New York.

Irwin-Williams, Cynthia, Henry Williams, George Agogino, and C. Vance Haynes. 1973. Hell Gap: Paleo-Indian Occupation on the High Plains. Plains Anthropologist. 18(59):40-53.  

Peck, Trevor R. 2011. Light from Ancient Campfires. AU Press. Edmonton.  

Stanford, Dennis. 1999. Paleoindian Archaeology and Late Pleistocene Environments in the Plains and Southwestern United States in Ice Age People of North America, edited by Robson Bonnichsen and Karen L. Turnmire. Oregon State University Press. Corvallis.    

Taylor, Jeb. 2006. Projectile Points of the High Plains. Sheridan Books. Chelsea.   

About the Author. 

John Bradford Branney started collecting prehistoric artifacts in Wyoming with his family at the ripe old age of eight years old. He has amassed and documented a prehistoric artifact collection numbering in the thousands. He has written eleven historical fiction books and over ninety papers focused on Paleoindians, prehistoric artifacts, and geology. Branney holds a B.S. degree in geology from the University of Wyoming and an MBA in finance from the University of Colorado. He lives in the Colorado Mountains with his family.