3. Anzick, Montana: The Anzick site in Montana is reported to be a Clovis burial and cache. At
Anzick, 12 radiocarbon dates were obtained from the cranial elements of a purported Clovis
infant skeleton and 2 dates on associated bone foreshafts. Collagen extracted from the foreshafts
yielded an average age of 11,040 + 35 14C yr B.P. (S7). The human skeletal remains were dated
during three separate research programs. The first batch of seven dates on bone comprise five
chemical fractions that were considered reliable and averaged to 10,680 + 50 14C yr B.P. (S2).
Later, a single purified collagen sample yielded a date of 11,550 + 60 14C yr B.P. (CAMS-
35912). This measurement is rejected because subsequent dating of the same XAD fraction and
preceding fractions from newly sampled bone did not replicate the 11,550 14C yr B.P. result.
The source of the contaminating 14C-depleted carbon is unknown. A more recent series of dates
from a single cranial fragment provided four new radiocarbon ages. These fractions confirm
previous date estimates for the skeleton of 10,705 + 35 14C yr B.P. The 14C dates on the skeleton
versus the dates on the bone foreshafts suggest that the skeletal remains and Clovis artifacts may
not be related and that the foreshaft ages more accurately date the site. The 10,700 year old
human remains could post-date the Clovis cache, but additional research is needed to resolve this
issue. A more recent, late Paleoindian or early Archaic human skeleton was also found at the
site (S7). The association of any of the human remains with the Clovis cache is problematic
because the site had been excavated accidentally with heavy machinery before the human bones
and artifacts were recognized and later recovered at some distance from the actual site. Thus, the
directly dated Clovis artifacts—the foreshafts—appear to accurately date the site.