Colorado State anthropologists and students have begun excavating an archaeological site in Windsor where researchers believe bison were killed by Indians 2,000-4,000 years ago.
The bison bone bed, discovered in a developing subdivision, contains unusually well-preserved bones and is one of only a few bison kill sites in Colorado dating from the late Archaic period. When bones and an arrowhead were found protruding from a newly cut hillside last fall, a Colorado State team gained permission to perform test excavations. The team determined the site was historically significant and organized the comprehensive dig that began this week.
"Bison bone beds are fairly common in the West, but finding a bison kill site from this time period in Northern Colorado is very rare," said Larry Todd, associate professor of anthropology at Colorado State. "This is an opportunity to reconstruct the late Archaic period. This site is also unique because of the excellent preservation of bone, which will allow us to do extremely accurate analysis. Our test excavations indicate the site was buried with sediment soon after the kill event, which kept the bones in pristine condition. They show cut marks, which are clear evidence of human butchery."
Todd and his assistant, Chad Jones, an anthropology graduate student, will lead a team of 15 undergraduate and graduate students and volunteers in unearthing the layer of bones located in what researchers think is an old creek bed where two drainages converged. The area has been named the Kaplan-Hoover Bison Kill Site, after Les Kaplan, the land owner and president of River West Development Corp., and Gary Hoover, the owner of the company constructing the new subdivision. The two men have given Colorado State permission to excavate.
"We believe 30-50 bison were killed by Indian hunters who drove them over the edge of a cliff or ran them into the arroyo," said Jones. "The bones not only show marks made by stone tools, but also marks made by carnivores that may have scavenged the site after the people left."
Colorado State students and anthropologists will work at the site through July 16, recording every object larger than a centimeter. Jones said that the careful excavation effort will reveal more details about the kill event, but that researchers also hope findings will give them broader insight into human activities, animal life, climate and vegetation on the plains thousands of years ago.
Excavation is just the beginning of the project for Colorado State researchers. "Archaeological research takes six months to a year in the lab for every month spent on the site," said Todd. "So the excitement of discovery will continue long after the excavation is complete. The collection of bones becomes a reference library for anthropology students."
Through analysis of the bison bones and teeth, researchers will learn about the composition and health of the herd, including the ages and numbers of bulls, cows and calves. Chemical analysis will help determine what types of grasses the animals ate and how much grit was in their diet. These data will indicate how dry the climate was at the time.
"When we have a well-preserved site like this, we’re able to get a highly accurate record of past rainfall and climate patterns," said Todd. "This can aid in developing methods for today’s land management."
Anthropologists will also analyze the site to determine the season of the kill. Studying the marks on the bones will indicate how much meat and what cuts of meat were taken. The arrowhead found at the site and other tools that may be uncovered will offer further clues about the Indians’ lifestyle.
"By looking at the type of stone used to make tools we can guess where these Indians came from and which direction they were moving," said Todd. "This can help in charting the flow of people across the plains."
With new DNA testing technology, scientists can identify similarities between the bison that were killed at the Kaplan-Hoover site and bison found at other sites. This technology could answer questions about the typical size of bison herds and how they migrated.
Visitors are welcome to tour the Kaplan-Hoover Bison Kill Site during designated hours. The site is open for visits from 9 a.m.-3 p.m. May 29-June 4; June 9-18; June 23-July 2; and July 6-16. The site is in the River West Housing Development, located two-and-a-half miles east of the Windsor exit off I-25. Large groups and people with special needs should call Chad Jones in the Center for Human Paleoecology at (970) 491-5110 to schedule a tour.
Funding for the excavation is provided by the College of Liberal Arts and the department of anthropology.