Mammoth Wenas. Source: CWU.edu; painting by Bronwyn Mayo.
For the past few years, students and faculty from Central Washington University have been excavating terminal Pleistocene fauna, including a partial mammoth skeleton, from the Wenas Creek area just north of Yakima (map), and they have a nice website documenting their work. Radiocarbon dates on the mammoth came back at 13,400 and 14,000 radiocarbon years ago, or about 16,000 calendar years ago. Too old for archaeological interest! Right?
Flake FS261, found (sort of) associated with Mammoth. Source: Lubinski et al. 2009; I tweaked the colour balance.Scale bars are one cm. each
Well, probably. But the fact is, three chert flakes have been found in the dig, two of which are fairly conclusive looking, and one of which has pretty good provenience. The preliminary report authors (Lubinski et al 2009; download PDF) are admirably restrained about the associations and even the artifactuality of these flakes, and more power to them for that. Nonetheless, the picture above shows a pretty plausible chert flake (see also: Current Research in the Pleistocene, 2009; PDF). Vertically, this flake was found 15 cm above the mammoth bones. However, we know that stratigraphy does not always lie horizontally, and when the backplot is considered (below) then we see a much more likely association between the mammoth, a probable Bison antiquus, and the flake. A luminescence date on Unit II sediments came back at 14,000 +/- 1,000 years ago. As you can see, the overlying unit is loess, likely the result of terminal Pleistocene deglaciation processes. The luminescence dates and radiocarbon dates (five altogether) are in stratigraphic order and the geoarchaeology seems right, and tight.
Backplot of Wenas stratigraphy showing flake FS261 ("artifact") in relation to sloping stratigraphy. Source: Lubinski et al. 2009.
So: much too early to make a big deal of this find, which is still unfolding – faunal analysis is incomplete and the project may only now be zeroing in on the cultural component. The timing is a bit early even for my comfort zone, but we do know the coastal route would have afforded access by about 16,000 calendar years ago, after a time when Vancouver Island and Puget Sound were briefly over-run by ice about 17,500 to 16,000 calendar years ago (Puget Sound animation – dates are calendar years BP). The site location on the eastern slopes of the Cascades would imply people crossing a major pass quite early – or, with glacial down-wasting being a top-down process, perhaps the mountain ridges formed viable corridors at that time.
Still, quite exciting as paleontology at least, and it seems they are running their field school again this summer, so go sign up and report back in August. There’s another good writeup here, which gives a flavour of the dig and some more pictures; on the left hand of the CWU page there are links to project videos as well.
Update: I just noticed that the owners of the property, Doug and Bronwyn Mayo, who have been very co-operative with all aspects of scientific research, also have a web site about the mammoth and you can buy some very nice Wenas Mammoth merchandise from them.
Another chert flake from Wenas Creek mammoth site. Source: Lubinski et al. 2008. Colour balance tweaked.
References:
Lubinski, Patrick M. 2008. The Wenas Creek Mammoth Project: 2008 Interim Archaeology Report on Excavations at 45YA1083 Final Submission July, 2009. With contributions by Bax R. Barton, Karl Lillquist, Patrick T. McCutcheon, Morris Uebelacker, and Brian Whiting. PDF.
Lubinski, Patrick M., Patrick T. McCutcheon, Karl Lillquist, Morris Uebelacker, Bax R. Barton, and Jake T. Shapley 2009. Possible Lithic Artifacts from 2005–07 Excavations at the Wenas Creek Mammoth Site. Current Research in the Pleistocene, 26: 85-86. PDF
Northwest Coast Archaeology 
The flakes look pretty convincing, especially the first. Chert? How much colour tweaking did you do?? I guess that they are geologists and geographers, they should know! The profile makes any association look much less convincing; the bones follow a clear path, and a short extension takes you well under the flakes; as the very good layperson’s account of a dig visit says, an inch might mean a few thousand years or it might mean the same day. If that luminescence date on the colluvium is anything close to right, even if the flakes post-date the mammoth, they are still astoundingly early! Looking forward to more.
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Hi Morley,
This is the untweaked version:
I lightened it a bit because the first time the cut and paste made it very, very dark and didn’t show that narrow dorsal flake scar – the new link in this comment is more reflective of the publication for some reason. I agree it doesn’t look much like chert, being translucent and fuchsia and looking a bit granular. The third flake is described as petrified wood.
The provenience on none of these flakes is ironclad – and this one is only 25 cm below modern surface in a general area with other sites present. The others are deeper. But if the context is they are sealed under loess, that is interesting in its own right. A luminescence date on the loess would be good to obtain. The two PDFs linked at the end give some good detail. As you say, this will be interesting to follow.
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There’s a new paper on the Wenas mammoth artifacts in the new Journal of Archaeological Science. The authors are extremely cautious, noting simply that they can’t rule out two artifacts as being of the made-by-people kind, not “geofacts” or charmingly “equifacts”. Anyway, from their conclusions are mild:
Given the stratigraphy and dating of the site, reasonable interpretations can range from the idea that there are two possible artifacts from 17 ka to the idea that there are two later, genuine artifacts intruded into a 17 ka paleontological site. If these two specimens are in fact human-made artifacts, and if they are asso- ciated with the well-dated 17 ka mammoth and bison bones, given the relative dearth of pre-Clovis age sites, it would have implica- tions for our understanding of the peopling of the Americas. [editor: no shit] However, the evidence from the Wenas Creek Mammoth site is not sufficiently strong to make this assertion, given the uncertainty about whether the specimens are in fact artifacts and the uncertainty about their age.
Comparative methods for distinguishing flakes from geofacts: a case study from the Wenas Creek Mammoth site
Patrick M. Lubinski a, b, *, Karisa Terry a, Patrick T. McCutcheon a, b
Journal of Archaeological Science 52 (2014) 308-320
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