National Park Service


Date of this Version



The Department of Agriculture, United States Forest Service Ashley National Forest Vernal, Utah Ashley National Forest Report No. AS-04-1010


Executive Summary

In 2003 a partial bison skull was recovered by Ashley National Forest archeologist Brian Storm from an elevation of 3840 m (12,600 ft) AMSL in the Uinta Mountains. The partial skull consists of a portion of the frontal, occipital region, and horn cores including horn sheaths. The presence of the horn sheaths is of particular interest for the ecological information they can provide. Through the analysis of the individual cones of the horn sheath a record of the animal’s dietary and migration patterns can be obtained.

The skull was recovered downslope of Gilbert Peak in an alpine environment. Tundra vegetation characterizes the area. Downslope, and to the east, of the skull find is the headwaters area of the Uinta River. This boggy area is drained by Gilbert Creek with wet meadow vegetation and Engelmann spruce along the edge.

While high altitude bison remains have been discussed in the scientific literature periodically over the past 80 years they have not gone beyond the descriptive. The study of this specimen focuses on a more complete understanding of bison ecology in the intermountain west. In addition to metric analysis of the skull, radiometric assay, and stable isotope analyses were applied.

The radiocarbon age of the specimen is 150 ± 40 yrs BP. The 2 sigma calibrated age is cal AD 1660 to 1950. Metric analysis of the skull indicates it was an adult male, at least 10 years of age, that compares well with Bison bison athabascae in size and is larger than either Bison bison bison specimens or other high altitude bison. However, it is probable this individual represents a member of the species Bison bison bison, but phenotypic characteristics (e.g., large horn size) may be the result of gene flow. More definitive taxonomic placement of the Gilbert Peak bison may not be resolved without genetic analysis.

Temporal and spatial gaps in the Holocene record of bison still exist and isolated skulls can help fill them. Detailed analyses of these specimens can provide an understanding of the history, the paleoecology, and evolution of the species. The results of this study begin to fill this gap.