Late Pleistocene and Holocene Bison of the Colorado Plateau: Are Bison Native to the Greater Grand Canyon Area?

By Jeff M. Martin, Rachel A. Short, and Jim I. Mead

Editor’s Note: Jeff is a PhD candidate in Wildlife and Fisheries Sciences at Texas A&M University. He earned his BS in Geology and MS in Geosciences from East Tennessee State University and was an PCP-PIRE intern in 2012.  Rachel is a PhD student in Ecosystem Science and Management at Texas A&M University. She earned her BA in Biology from Illinois Wesleyan University, and MS degrees from East Tennessee State University (Geosciences) and University of Maine (Teaching). Jim earned his MS and PhD in paleoenvironmental studies (Geosciences) from the University of Arizona.  He is now the chief scientist and site director at The Mammoth Site, Hot Springs, SD, having retired from 33 years in academia.

Jeff Martin and Rachel Short
Jeff and Jim Mead

Few animals in North America possess the cultural, spiritual, ecological, economic, political, and natural history attributes of the North American bison. Certainly, no other North American animal has gone to the brink of extinction twice—during the megafaunal extinction at the end of the Pleistocene and then during the late 1800s when Euro-Americans hunted nearly all that existed at that time.

Today, nearly 400 bison live in and around Grand Canyon National Park. Management of the herd is complex because the animals are property of the State of Arizona (Arizona Game and Fish Department, AZGFD), but the herd meanders onto the North Rim of the Grand Canyon and uses the natural resources of the Kaibab Plateau (Martin, 2014). Moreover, while the State of Arizona has designated bison a native species, the Grand Canyon National Park regards them as nonnative and human (re)-introduced. Wildlife, including bison, do not adhere to arbitrary boundaries. As such, wildlife biologists must use science-based precedence, including wildlife nativity, to determine management strategies and protocols (Martin and Mead, 2014). In this case, nativity means naturally occupying an area through time. However, managing transient wildlife across Federal and State lands is not simple because of differing goals of agencies that, in this case, include the U.S. Forest Service, the National Park Service, and the AZGFD. For instance, according to the State of Arizona, bison are a native species; yet, Grand Canyon National Park does not have the same designation. Conflict between agencies can have cascading effects on management decisions and, in an effort to resolve this, we examined the nativity of bison on the Colorado Plateau (Martin et al., 2017).

Although there are fossil records of Bison in many areas of the western United States, few Bison fossils have been found in the arid Southwest—especially in and around the Greater Grand Canyon Region. Today, there are fenced areas near the Grand Canyon, but the Grand Canyon ecosystem extends beyond the property boundaries and is referred to by us as the Greater Grand Canyon area. We looked at the Greater Grand Canyon area ecosystem and the Colorado Plateau physiographic region as potential areas where Bison could have lived prior to the fencing of the West. We reviewed undocumented and misidentified specimens from archaeological and paleontological localities archived in collections at the Museum of Northern Arizona, at the Grand Canyon National Park, and at the East Tennessee State University Vertebrate Paleontology lab. The previously undescribed specimens consist predominately of dung and skeletal remains from cave, rock shelter, and packrat midden localities. We also located occurrences of Bison from the following online data sets: Neotoma Paleoecology Database (NeotomaDB,; Arizona’s Cultural Resource Inventory (AZSite, and Neogene Mammal Mapping Portal (NeoMap,

Poor fossil preservation introduced a collection bias that caused previous researchers studying faunal distributions to assume that bison were not native, even with evidence from paleontological, archaeological, and historical sites. A seemingly unintended outcome of this assumption was the erroneous taxonomic identification of some specimens. For example, 13 localities were found to have Bison fossils that were previously mislabeled as Pleistocene horse (Equus) and Anthropocene cattle (Bos taurus; Balkwill and Cumbaa, 1992). In total, we located 74 Bison-bearing fossil, subfossil, and historical localities (for a complete listing of localities, see Martin et al., 2017) since the latest Pleistocene (~160,000 years ago).

In conclusion, our findings indicate that Bison bison should be considered a native species on the Colorado Plateau because they have a nearly continuous record of nativity in the region (see Table 1). This information is valuable for public natural resource managers at GCNP and beyond.

Table 1
Years BP Pecos Classification Geologic Time Bison Localities
160,000 – 14,300 Preanthropogenic Late Pleistocene 14
14,300 – 10,000 PaleoIndian Latest Pleistocene 8
10,000 – 1,300 Archaic Early to Late Holocene 15
1,300-850 Pueblo I-II Latest Holocene 14
850 – 650 Pueblo III Latest Holocene 8
650 – 400 Pueblo IV Latest Holocene 12
400 – Present Pueblo V Latest Holocene 3


Table 1. Temporal summary of Bison localities on the Colorado Plateau using the Pecos Classification system of the American Southwest. Abbreviations: “BP”, calendars years before present.


Balkwill, D. M., and S. L. Cumbaa. 1992. A guide to the identification of postcranial bones of Bos taurus and Bison bison. Syllogeus 71:277.

Barnosky, A. D., et al. 2017. Merging paleobiology with conservation biology to guide the future of terrestrial ecosystems. Science 355(6325):eaah4787. Available from:

Martin, J. M. 2014. “Late Pleistocene and Holocene Bison of Grand Canyon and Colorado Plateau: implications from the use of paleobiology for natural resource management policy.” M.S. thesis, East Tennessee State University, Johnson City, Tennessee. Available from:

Martin, J. M., and J. I. Mead. 2014. Re-evaluation of Bison remains from the greater Grand Canyon region and Colorado Plateau: native or non-native? In: 10th North American Paleontological Convention, At Gainesville, Florida. Vol. 13. p. 59.

Martin, J. M., R. A. Martin, and J. I. Mead. 2017. Late Pleistocene and Holocene Bison of the Colorado Plateau. Southwestern Naturalist 62(1):14–28. Available from:



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