The Interagency Agreement Between the Department of the Army (DOA) and the Department of the Interior (DOI), signed in March, 1998, delegated responsibilities to the DOI for certain decisions related to the set of human skeletal remains recovered from land managed by the Corps of Engineers (COE) near Columbia Park, Kennewick, WA. The agreement calls for the DOI to investigate and resolve two basic issues. First, we must determine whether or not the remains meet the definition of "Native American" according to the definition in the Native American Graves Protection and Repatriation Act (NAGPRA), as interpreted by DOI. Second, if the remains are Native American, the DOI will determine their disposition under the requirements of NAGPRA.
This memorandum describes the basis for the determination of the first of these actions, that is, whether or not the Kennewick skeletal remains are considered "Native American", as defined by NAGPRA.
As defined in NAGPRA, "Native American" refers to human remains and cultural items relating to tribes, peoples, or cultures that resided within the area now encompassed by the United States prior to the historically documented arrival of European explorers, irrespective of when a particular group may have begun to reside in this area, and, irrespective of whether some or all of these groups were or were not culturally affiliated or biologically related to present-day Indian tribes.
If this set of remains is found to fit within the category of "Native American," issues related to cultural affiliation will be highly relevant to how disposition of the remains should be accomplished. However, this will be a subsequent step in our assistance to the DOA and is not addressed further in this memorandum. We currently are investigating the possible cultural affiliation of these remains.
The Kennewick Skeletal Remains are "Native American" as Defined by NAGPRA
We now have sufficient information to determine that these skeletal remains should be considered "Native American" as defined by NAGPRA. The results of recent radiocarbon dating of small samples of bone extracted from the remains were given significant weight in making this determination. This interpretation is supported by other analyses and information regarding the skeletal remains themselves, sedimentary analysis, lithic analysis, an earlier radiocarbon date on a bone recovered with the other remains, and geomorphologic analysis (summarized in McManamon 1999).
A series of radiocarbon dates now available from the Kennewick skeletal remains indicate a clearly pre-Columbian date for the remains (Table 1 and discussed below). It is reasonable to conclude that the human remains from Columbia Park in Kennewick, WA, are "Native American" as defined by the Native American Graves Protection and Repatriation Act.
A variety of additional scientific information support this chronological placement and determination. Geomorphologic and sedimentary investigations of the river bank near the discovery site (Wakeley et al. 1998; Huckleberry et al. 1998) indicate that sediment layers consistent with these dates exist in the alluvial terrace where we believe the remains were buried originally. The documentation, examination, and analysis of the skeletal remains themselves (Powell and Rose 1999) suggest a pre-Columbian context for the remains. Comparison of sediments adhering to the skeletal remains and sediments from the river bank profile are consistent with the skeletal remains having been buried in sediments stratigraphically dated pre-7000 BP (Huckleberry and Stein 1999). Information from the analysis of the lithic artifact lodged in the ilium of the skeletal remains also is consistent with an ancient date for the remains themselves (Fagan 1999). In all, information derived using the methods and techniques of archeology, geomorphology, physical anthropology, sedimentology, and other scientific disciplines support this determination.
Our determination that the Kennewick skeletal remains are "Native American" is based upon the scientific information that we have available. As explained in subsequent sections, this a reasonable determination based upon such information now on hand.
Summary of the Radiocarbon Results
Four C14 dates have been reported for the samples extracted by the Department of the Interior and Corps of Engineers in September, 1999. The samples have been processed and dated by Beta Analytical, Inc. (BA), of Miami, Florida, the Radiocarbon Laboratory of the University of California, Riverside (UC-R), and the NSF-Arizona AMS Facility of the University of Arizona (UA). Two of the four new dates show a substantial conformance with the initial radiocarbon date of the portion of the metacarpal submitted by Benton County in 1996 (see Table 1). All the carbon samples showed very low carbon content and this has slowed the processing of the samples and extended the time required to develop our interpretation of the C14 dates.
The BA date (Beta-133993) gave a conventional radiocarbon age of 8410 +/- 40 BP (Hood 1999a and Attachment 1). The equivalent calibrated radiocarbon age (using the two sigma, 95% probability) in years BP is cal BP 9510 to 9405 and cal BP 9345 to 9320. The bone sample used for this date was approximately half of the right metatarsal, one of the load-bearing bones of the foot (Sample DOI 1a). Analysis and processing of the sample at Beta indicated that the amount of organic carbon remaining in the sample was very low. The Laboratory Director of BA, Mr. Darden Hood, reported that "the original weight of the bone was 9.1 grams. The amount of collagen extracted was 0.030 grams (30.0 mg). This relates to a percent concentration of 0.3%. The value is very low due to the high mineral content of the submitted bone. 9.5 mg. of the collagen was used for the analysis. This provided us with 3.2 mg. of carbon. The percentage of carbon is then calculated as 33.7% carbon within the collagen (Hood 1999b and Attachment 2)." Mr. Hood also reported that "by our standards, the collagen extract looked free of intrusive elements.It was vitreous in texture and golden in color as expected. It was free of visible contamination or deterioration. However, this does not preclude the presence of secondary [i.e., intrusive] environmental proteins (Hood 1999c)."
The Radiocarbon Laboratory of the UC-R processed and dated two of the Kennewick bone samples (Taylor 1999 and Attachment 3). Like the BA sample, both of these were very low in carbon content. Due to the low carbon content and the lack of clear collagen-like characteristics of the extracted carbon, the dates were reported as "the apparent C14 ages" for each sample (see Table 1). One of the samples (Sample DOI 1b) was dated as 8130 +/- 40 BP (UCR-3806/CAMS-60684), slightly different from the BA date for Sample DOI 1a, but not inconsistent with it. These two samples, in fact, are from the same bone, the right first metatarsal.
Both of these dates (Beta-133993) and (UCR-3806/CAMS-60684) are consistent with the earlier C14 date obtained from a portion of the 5th left metacarpal (Taylor et al 1998). The BA date, in fact is almost identical to the first C14 date.
The other UC-R date is also old, an apparent C14 age of 6940 +/- 30 BP (UCR-3806/CAMS-60683), but more recent than the other dates. This sample (Sample DOI 2b) from the left tibial crest also is more deteriorated than Sample DOI 1b. Sample DOI 2b contains only 2.3% of the carbon relative to the UC-R modern bone standard while Sample DOI 1b contains 14.3% of the modern standard.
The UA laboratory dated the second subsample from the left tibial crest (Sample DOI 2a). The date they obtained is also old, 5570 +/- 100 BP (AA34818). This date is more or less consistent with the UC-R 3806/CAMS-60683 date and together they suggest that exogenous "new carbon" is pronounced in the left tibia from which these two samples were taken. The UA laboratory also reported a low carbon content for Sample DOI 2a (Donahue 2000a and b and Attachments 4a and 4b). They recorded a carbon yield of .05 %, that is, the final mass of carbon based upon the initial mass of the bone. UA's analysis of this level of carbon content was that they could not determine the source of the carbon, i.e., whether it was inherent or exogenous.
Low Carbon and Possibility of Intrusive Contamination
One problem with dating bone samples with low carbon is that exogenous or intrusive carbon may have infiltrated the bone and become mixed with the endogenous or inherent carbon. If treatment of the sample before dating is not able to remove the intrusive carbon, any date from the sample will be distorted by the intrusive carbon. In most cases, it is younger carbon that is intrusive, for example, carbon from plant roots, soil microorganisms, or humic organic compounds in the soil. Usually such sources of exogenous carbon post-date the death and burial of the bone being dated. The effect of such mixing of "new carbon" with the original carbon in the bone is to make the date of the bone appear more recent than the true date.
In the case at hand, this may be the reason for the date from Sample DOI 2b. Taylor suggested this in his report on the C14 dating of the samples done by UC-R. "One interpretation [of the difference between the original date and the dates from these samples] is that the age offsets reflect varying percentages of more recent and/or modern contamination in both UCR-3806 and UCR-3807, with the percentage contribution of contamination increasing as a function of the decreasing residual collagen protein content (Taylor 1999a:1-2)."
If the only probable risk of intrusion by exogenous carbon is from more recent or modern carbon, as seems likely, the dates for the Kennewick bone samples indicate strongly that the remains definitely are pre-Columbian, and therefore "Native American" as defined by NAGPRA.
In certain geomorphologic circumstances, bone can be infiltrated by older carbon. If such "old carbon" is not removed in treatment prior to dating, dates will be distorted by appearing older than the bone itself. The geomorphic context in which we believe the Kennewick skeleton was buried and rested for many centuries is unlikely to have been affected by such contamination. There appears not to be an accessible and likely source for such carbon. Limestone, a common source of old carbon, is not prevalent in the watershed. Nor has there been much of an opportunity for such intrusion to have occurred through groundwater immersion of the bone by old carbon saturated water (Huckleberry et al. 1998; Wakeley et al. 1998) .
Difference with the 1996 C14 Sample
The low amounts of carbon detected in the DOI samples extracted from the right metatarsal and left tibia of the Kennewick remains differ substantially from the carbon content of the bone sample (portion of the fifth left metacarpal) submitted to the UC-R Archaeology Lab by the Benton County Coroner's office in August, 1996. The carbon content of this sample (UCR-3476/CAMS-29578) has been reported by UC-R as ".68.8% of our modern reference sample and the relative concentrations of amino acids was similar to that observed in our modern bone standard.(Taylor et al. 1998:1171-1172)"
This discrepancy between the carbon content observed in the 1996 sample and the samples analyzed in 1999 calls into question the relationship of the earlier sample to the rest of the human remains. It is unexpected and unusual, although not impossible, for an individual human skeleton to exhibit widely different concentrations of collagen in bones from different parts of the body.
Prior to the detailed examination of the Kennewick human remains in February, 1999, reported by Powell and Rose (1999) there were questions concerning whether the skeletal elements collected during July and August, 1996, were from a single individual. Powell and Rose demonstrated that the remains obtained from the original collector by the Corps of Engineers and curated since September, 1996, by them indeed were from a single individual. Also arguing for these bones being from the same individual is the fact that three independent radiocarbon dates consistently show the bones to date between about 8000 and 8500 BP.
We have received a more detailed description by the archeologist who originally collected the remains in 1996 (Egan 2000). This information indicates that the bone used for the 1996 C14 date was similar to other bones in appearance and might have been better protected from long term deterioration. There appears to be a photograph of the bone fragment to compare with the other bones. We shall verify this information using the photograph as best we can.
The chronological information needed to make the determination that the Kennewick skeletal remains are "Native American" as defined by NAGPRA has been provided by the additional C14 testing conducted by the Department of the Interior and three radiocarbon laboratories. All the dates obtained predate 6000 BP and are clearly pre-Columbian. Two of the dates match closely the C14 date obtained in 1996 on another bone fragment believed to be from the skeleton.
Results of the earlier documentation, examination,
and analysis of the remains themselves, sediment analysis comparing
the sediment on the bones with sediment from the soil profile near where
they were recovered, analysis of the lithic point embedded in the left
ilium of the remains, and geomorphologic studies near the discovery
site also support this determination.
References Mentioned in Text
(2000b) Results of measurements to date on the Kennewick bone, equipment preparation, sampling procedure, and the pretreatment procedure. Letter, 9 January 2000. Included here as Attachment 4b. On file, Archeology and Ethnography, National Park Service, Department of the Interior.
Egan, James E.
Fagan, John L.
(1999b) Additional information regarding Beta Analytic's radiocarbon dating analysis of Kennewick bone sample CENWW.97.R.24(Mta)/DOI1a. Letter to Dr. Francis P. McManamon, 18 November 1999. Included here as Attachment 2. On file, Archeology Program, National Park Service, Department of the Interior.
(1999c) Background about the Kennewick C14 Samples. E-Mail to Dr. Francis P. McManamon, 9 December 1999. On file, Archeology Program, National Park Service, Department of the Interior.
Huckleberry, Gary, Thomas W. Stafford, and James C.
Huckleberry, Gary and Julie K. Stein
McManamon, Francis P.
Powell, Joseph F. and Jerome C. Rose
R. E. Taylor
R. E. Taylor, D. L. Kirner, J. R. Southon, and J. C.
Wakeley, Lillian D., William L. Murphy, Joseph B. Dunbar,
Andrew G. Warne, Frederick L. Briuer, and Paul R. Nickens
Attachment 1. Hood, Darden (1999a) Report of sample processing and dating. Letter to Dr. Francis P. McManamon, 17 October 1999.
Attachment 2. Hood, Darden (1999b) Additional information regarding Beta Analytic's radiocarbon dating analysis of Kennewick bone sample CENWW.97.R.24(Mta)/DOI1a. Letter to Dr. Francis P. McManamon, 18 November 1999.
Attachment 3. R. E. Taylor (1999) Results of the UCR Radiocarbon Analysis of two Kennewick Bones Compared with the Earlier Results. Fax to Dr. Francis P. McManamon, 20 December 1999.
Attachment 4a. Donahue, Douglas (2000a) Carbon-isotope measurements on the Kennewick bone. Letter to Francis P. McManamon, 10 January 2000.
Attachment 4b. Donahue, Douglas (2000b) Results of measurements, equipment preparation, sampling procedure, and the pretreatment procedure. Letter to Francis P. McManamon, 9 January 2000.