Research Article
The U.P. Mammoth Site, Carbon County, Wyoming, USA: More
Questions than Answers
C. Vance Haynes Jr.,1 Todd A. Surovell,2 ,* and Gregory W. L. Hodgins3
1
School of Anthropology, University of Arizona, Tucson, Arizona
2
Department of Anthropology, University of Wyoming, Laramie, Wyoming
3
NSF-Arizona, AMS Facility, Department of Physics, University of Arizona, Tucson, Arizona
Correspondence In the summer of 1960, mammoth bones were discovered by a dragline opera-
*Corresponding author; tor in southern Wyoming at the Union Pacific (U.P.) Mammoth site. Although
E-mail: surovell@uwyo.edu
subsequent archaeological work during 1960 and 1961 identified artifacts in
Received association with the mammoth remains, many authors have since questioned
20 June 2012 the nature of that association. Also, little has been published about the site
Accepted other than a brief article in National Geographic Magazine in 1962. In this pa-
11 December 2012 per, we present additional information on the U.P. Mammoth site including
stratigraphic profiles from the first author’s geoarchaeological work in 1961,
Scientific editing by Gary Huckleberry
stratigraphic and spatial location of bones and artifacts derived from the origi-
Published online in Wiley Online Library nal field notes, and new radiocarbon dates. Although the precise stratigraphic
(wileyonlinelibrary.com). provenance for many artifacts and skeletal elements remains unclear, a com-
pelling argument can be made for spatial and stratigraphic association of the
doi 10.1002/gea.21433 mammoth remains with the artifact assemblage suggesting some kind of hu-
man interaction with the animal. C 2013 Wiley Periodicals, Inc.
INTRODUCTION ation between the artifacts and mammoth remains that,
along with new radiocarbon dates, provides additional
At the Union Pacific (U.P.) Mammoth site, artifacts were data relevant to the hypothesis of cultural association.
discovered in association with the remains of Columbian In the summer of 1960, the first author was called to
mammoth (Mammuthus columbi), and although the initial the University of Wyoming by Anthropology Professor
report on the site suggests that its investigators had little George A. Agogino for the purpose of examining and
doubt about the meaning of that association (Irwin, hopefully dating the skeleton of a mammoth that had
Irwin, & Agogino, 1962; Irwin, 1970), others who have been uncovered at Sage Chicken Spring about 50 km
examined the evidence since are less certain. On the southwest of Rawlins, Wyoming (Figure 1). The bones
basis of the artifacts that were discovered, patterns were exposed in August by Mr. Ivan Hays while deepen-
of bone modification, and the spatial arrangement of ing the spring with a dragline in order to increase water
skeletal elements, Irwin et al. (1962) interpreted the flow for a nearby drilling project. A few days later a large
site to represent a kill and butchery event. Citing Frison black bifacially flaked knife was found at the site in un-
(1978:29, 85), Grayson and Meltzer (2002:323) refer certain association. Dr. Brainerd Mears, a geomorpholo-
to the association of artifacts and mammoth remains gist from the University of Wyoming, who was assisting
at U.P. as “tenuous or nonexistent.” Frison (1978:29) in the initial excavations, claims the artifact was found on
suggests that some of the artifacts were recovered from the surface (George C. Frison, personal communication,
“questionable contexts” and was unable to examine all of 2011). It is made of “tiger chert” from western Wyoming.
the skeletal remains recovered to verify the presence of The following year a large yellowish brown jasper bifacial
human modification. Frison (1978), G. Haynes (1991), knife was recovered from near the axis vertebra, along
and Cannon and Meltzer (2004) all have lamented that with many less spectacular stone tools from the excavated
the results of the investigations at the site were never areas.
fully published. In that light we here present additional Because Agogino did not like calling the mammoth site
information on both the stratigraphic and spatial associ- the Chicken Springs site, he decided to name it the U.P.
Geoarchaeology: An International Journal 28 (2013) 99–111 Copyright
C 2013 Wiley Periodicals, Inc. 99
, THE U.P. MAMMOTH SITE, CARBON COUNTY, WYOMING, USA HAYNES ET AL.
Figure 1 Location map for the U.P. Mammoth site, Carbon County, Wyoming.
Mammoth site, mistakenly believing it was on their prop- Stratigraphic relationships as revealed by excavations
erty or lease. It is here shortened to the U.P. site, but a are shown in Figures 5 through 7. Bedrock sandstone,
new name is called for as explained later. coal, and shale of the Tertiary Lance Creek Formation
Formal excavations by crews from Harvard University dip 5◦ –10◦ northwest. A coal bed at the site is the lo-
under the direction of Henry and Cynthia Irwin (brother cal aquifer, and its intersection with the draw produces
and sister) and from the University of Wyoming under the spring seepage that today maintains a wet meadow
the direction of George Agogino were conducted during or cienega.
the summer of 1961, with support of the National Geo-
graphic Society (Irwin, Irwin, & Agogino, 1962). The first
author was the project geologist. An 80 ft × 50 ft (48 m ×
15 m) area was laid out by the archaeologists at 45◦ to
STRATIGRAPHY
the cardinal directions and divided into a grid with 5-ft Six stratigraphic units (A–F and subdivisions thereof)
(1.53 m) squares (Figure 2). Five 5-ft-wide trenches, per- were identified in the excavations. The strata and their
pendicular to the local drainage, were extended 20 ft subdivisions were based on sediment type and color
(6.1 m) to the southwest from the bone and artifact con- as well as weathering criteria (soil development and
centration leaving 5-ft-wide balks between trenches, thus groundwater alterations). The paleosols developed on
providing three-dimensional exposures of much of the Strata D, C, and A are truncated by erosion, and, there-
stratigraphy that was subdivided into eight stratigraphic fore, are incomplete (Table I).
units (Figures 3 and 4; Table I). Table II is a correlation Stratum A is composed of clay and coal sand appar-
chart of stratigraphic designations of Table I with those of ently flushed from the coal and shale beds by spring
the archaeologists. discharge during a period of vigorous spring activity.
100 Geoarchaeology: An International Journal 28 (2013) 99–111 Copyright
C 2013 Wiley Periodicals, Inc.
