On a quiet stretch of Cheyenne County prairie south of Firstview, little is visible today to suggest that one of North America’s most remarkable archaeological discoveries once lay beneath the soil.
More than 10,000 years ago, Paleo-Indian hunters drove a herd of ancient bison into a narrow arroyo. Nearly 200 animals became trapped, piled together and were killed and butchered. Thousands of years later, drought and wind exposed their bones, setting in motion an excavation that brought local landowners, amateur archaeologists and University of Colorado researchers together on the eastern Colorado plains.
That history returned to the forefront Saturday, July 25, when the Eastern Colorado Historical Society hosted a presentation in Cheyenne Wells about the Olsen-Chubbuck Site.
Dale Dwyer, whose family owned and worked the land when the excavation occurred, shared memories, photographs and family stories connected to the dig. His account offered something formal archaeological reports cannot fully provide: a picture of what happened when university professors and students arrived in rural Cheyenne County and began uncovering what came to be known as a “river of bones.”
The Olsen-Chubbuck Site dates to the Paleo-Indian period. Current University of Colorado descriptions generally place the hunt at approximately 8200 B.C., although earlier archaeological reports estimated a date closer to 6500 B.C.
The people responsible for the hunt had no horses, firearms or bows and arrows. They traveled on foot and used spears or throwing darts tipped with carefully shaped stone points.
The hunt required an understanding of the land, the wind and bison behavior. It also required cooperation on a scale far beyond one hunter pursuing one animal.
The extinct bison found at the site were identified as Bison occidentalis, a form generally larger than modern plains bison. Archaeologists determined that the animals represented a mixed herd that included mature bulls, cows, immature animals and calves.
The presence of very young calves helped researchers conclude that the hunt likely took place in late May or early June. The orientation of the animals and location of projectile points also suggested that the wind was probably blowing from the south.
Hunters would have needed to approach from downwind to avoid being detected. Bison possess a strong sense of smell but comparatively limited eyesight, allowing hunters to move closer under favorable conditions.
Researchers believe hunters positioned themselves around the herd and frightened the animals into motion. The bison stampeded toward a narrow arroyo that crossed the landscape.
At the western end, the arroyo was relatively shallow. Farther east, it became considerably deeper. Once the leading animals entered the channel and began to fall, those behind could not stop. They continued forward, trapping and crushing animals already below.
The excavation revealed bison lying in twisted positions, some pinned beneath several others. Many at the bottom remained complete or nearly complete because the hunters could not reach or move them. Animals closer to the top were butchered much more extensively.
Joe Ben Wheat, the University of Colorado archaeologist who directed the professional excavation, wrote that the site preserved the hunt in remarkable detail. The position of the skeletons, the direction they faced, the placement of projectile points and the organized piles of bones allowed researchers to reconstruct portions of what happened that day.
The deposit stretched more than 170 feet along the center of the ancient arroyo. Archaeologists documented the remains of nearly 200 bison, including 13 complete or nearly complete skeletons in the deepest layer.
Dwyer described the excavation as a stair-stepped trench that became deeper as it moved from west to east. Photographs shown during the presentation illustrated why the deposit became known as the “River of Bones.”
Skulls, ribs, spinal columns, shoulder blades, pelvic bones and legs were densely packed inside the channel. In some areas, bones were arranged in separate piles according to body part.
Those piles revealed that the butchering process was organized rather than random.
The hunters apparently moved several animals into workable positions at the same time. They rolled the bison onto their bellies, spread the legs, opened the hide along the back and peeled it down over the sides. The hide created a surface on which meat could be placed during the work.
The tender meat along the back was removed. The front legs and shoulder blades were separated, exposing the hump meat, rib cage and internal organs. The hindquarters were removed from the pelvis, followed by the neck meat, skull and tongue.
Archaeologists identified repeated “butchering units”—groups of forelegs, pelvic sections, hind legs, spinal columns and skulls deposited in a similar order. The consistency suggested that several carcasses were being processed at the same time by people following a shared method.
“The way in which the butchering units were grouped suggests that several bison were moved into position and cut up simultaneously,” Wheat wrote in his 1967 Scientific American article, “A Paleo-Indian Bison Kill.”
The hunters made practical use of nearly every part of the animal. Meat, organs and fat provided food. Hides could be used for shelter, clothing or containers. Sinew could become cordage, while bones could be fashioned into tools.
Wheat estimated that the animals could have yielded approximately 56,640 pounds of meat, in addition to roughly 4,000 pounds of edible organs and 5,400 pounds of fat.
Based on the amount of food available and the work required to process and transport it, Wheat estimated that the hunting band may have numbered approximately 150 people. His calculation was not proof that all 150 individuals participated directly in the stampede or butchering, but it demonstrated the size of the community that could have benefited from the kill.
Dwyer suggested that the several days of processing may have resembled a large communal gathering, with normally separate groups working and eating together.
What happened after the hunters departed remains uncertain. Researchers do not know exactly where the group camped or which direction it traveled afterward.
Over centuries, windblown soil filled the arroyo and buried the bones. The evidence remained hidden beneath the prairie for thousands of years.
The site might have remained buried indefinitely if not for severe drought and wind erosion during the 1950s.
Dwyer explained that members of his family had noticed bone fragments on the ground before the formal discovery. The property had been broken for farming, but dry conditions made raising crops difficult. Wind erosion during the drought years removed several inches of soil from portions of the hillside.
That erosion exposed white bone fragments in a line across the ground.
On Dec. 8, 1957, Gerald “Jerry” Chubbuck was traveling through the area while searching for signs of early camps. Near noon, he stopped on a rise, took his lunch and began walking across the property.
Chubbuck later wrote that he noticed pieces of white bone protruding from the hardpan. Among them, he found a sharp projectile point made from silvery-white stone. The point was of a type then often called Yuma and later classified as Scottsbluff.
Its presence suggested that the bones were not simply the remains of animals that had died naturally. A human-made stone point lying among them indicated an ancient hunting or butchering site.
Chubbuck returned to investigate further and later worked with Sigurd Olsen, a local rancher, collector and amateur archaeologist with a deep interest in the region’s early history.
The importance of their local role cannot be overstated.
Neither Chubbuck nor Olsen was a university archaeologist when the site was found. They were experienced observers who understood that bones, stone tools and their positions in the ground could reveal a much larger story. Rather than simply removing the artifacts as collectibles, they pursued professional guidance and worked to understand the site.
The discovery eventually took both of their names.
Chubbuck and Olsen conducted preliminary excavations and uncovered the remains of an estimated 50 animals before the University of Colorado assumed responsibility for the larger investigation.
During Saturday’s program, a descendant of Olsen also spoke about his grandfather’s interest in archaeology and regional history. He described Olsen as a rancher rather than a university employee, but one who valued books, learning and preservation.
The Olsen-Chubbuck excavation was not simply a case of outside experts arriving and making a discovery. Local people recognized the site, began documenting it and brought it to the attention of professional archaeologists.
After Chubbuck contacted the University of Colorado Museum, arrangements were made for Wheat to examine the site.
Wheat served as curator of anthropology at the University of Colorado Museum of Natural History and became one of the leading archaeologists studying the Great Plains. With permission from Chubbuck, Olsen and landowner Paul Forward, the museum took responsibility for completing the excavation.
The professional work was conducted mainly during the summers of 1958 and 1960.
Dwyer’s memories brought the academic excavation down to earth.
A crew that included college students arrived and initially camped near the site. Eastern Colorado weather quickly became part of the experience. Wind battered their tents, leading the group to move into an old farmhouse and barn on nearby family property.
The farmhouse became living quarters. Stalls in the barn were cleared or adapted into workspaces where bones could be cleaned, stabilized and prepared.
Excavation was painstaking.
Workers removed soil primarily with hand tools, including trowels and small brushes. Each bone had to be uncovered without disturbing its relationship to the surrounding bones and artifacts. Its position was mapped, labeled and photographed before removal.
Dwyer recalled that some bones began to crumble after being exposed to the air. The crew applied a diluted preservative to stabilize them before lifting them from the ground. Molds and casts were also made of selected specimens.
Local families supplied access to the property, places for the crew to live and work, equipment, practical assistance and knowledge of the land.
Dwyer recalled that family members once attempted to help loosen the hard ground with farm equipment—an approach that, he said with a laugh, did not please the professor responsible for the careful excavation.
The university team brought formal excavation methods, specialized knowledge and the ability to preserve and study the collection. Local residents provided the access and practical support needed to make that work possible.
Wheat’s team eventually documented the remains of more than 190 bison and recovered 47 artifacts associated with the kill. Of those artifacts, 27 were projectile points. The collection also included knives, scrapers, hammerstones and other stone tools.
The projectile points showed surprising variation. Most were within the Scottsbluff tradition, but Eden and Milnesand forms were also found.
A projectile-point type identified from the site was later named the Firstview point for the nearby Cheyenne County community.
The site was especially valuable because it preserved evidence of one major event rather than a location occupied repeatedly for generations. Archaeologists could study the bone bed almost as if it were a single frozen moment.
The deepest animals showed how the herd entered the arroyo and became trapped. The upper layers showed how accessible carcasses were butchered. Organized piles revealed the order in which body parts were removed. The calf bones helped identify the season, while projectile points offered clues about where hunters stood as they controlled the herd.
Together, the evidence demonstrated that Paleo-Indian communities possessed extensive knowledge, planning ability and social organization.
This was not a random or desperate hunt. It was a coordinated operation carried out by people who understood bison, terrain, wind and one another.
Today, the collection and excavation records are held by the University of Colorado Museum of Natural History.
The museum’s Olsen-Chubbuck materials include field notebooks, photographs, negatives, drawings, maps and other research records from the excavation. Wheat’s notes contain site plans, cross-sections, bone measurements, artifact records and detailed analysis.
During the presentation, Dwyer said he was not aware of a permanent public display containing the full collection. He also said university representatives have continued studying and working with materials from the site.
The location itself remains on private property. Dwyer reminded the audience that anyone interested in visiting should first obtain permission from the current landowner.
He also brought casts, photographs, publications and other materials connected to the excavation and discussed donating some of them to the Eastern Colorado Historical Society.
That local preservation is important.
Universities conserve collections and conduct scientific research, but historical societies preserve the human memories surrounding those collections: who provided the buildings, where the students slept, what happened when the wind struck their tents and how local families experienced an archaeological excavation unfolding in their own pasture.
The Olsen-Chubbuck Site belongs to a history far older than Firstview, Cheyenne Wells or Cheyenne County. But the story of its discovery and excavation is distinctly local.
It began when drought uncovered a line of bones. It continued because local people recognized that those bones mattered. It became an internationally significant archaeological study because landowners, amateur archaeologists, local families, students and professional researchers each contributed to its preservation.
Beneath an ordinary Cheyenne County field, the past had waited for thousands of years.
For a few summers in the late 1950s and early 1960s, the prairie opened—and a river of bones told its story.
