Microcore Technology in Northwestern Wyoming

 Submitted by

Craig M. Lee and Jennie B. Lee, Metcalf Archaeological Consultants, Inc. 


Microlithic technology in North America is most commonly associated with the microblades found in Arctic and Subarctic environments as well as the Northwest Coast; however, variations of the technology occur in other locations.  Unlike bifacial lithic tools that can exhibit life-cycles or stages of modification and reuse, microliths are essentially finished when they are produced and inset in an organic haft to make a composite tool; that is, a tool made of different materials.  In general, microliths provide an efficient way to produce large quantities of usable cutting edge from a given piece of stone. Plains Anthropologist recently published an article titled “Microcores and Microliths in Northwestern Plains and Rocky Mountain Front Lithic Assemblages” (Lee et al. 2016), which describes the occurrence of this technology in the region and complements Wilson et al.’s (2011) study of Cody-age microblade technology in the High River area of southern Alberta. 


Artifacts resembling microblade cores are occasionally referenced in the publications and grey literature of the Northwestern Plains and adjacent regions, where they are variously referred to as microblade cores, microcores, and conical or circular scrapers (e.g., Kornfeld et al. 1995; Roll and Neeley 2014 [Northwest Plains]; Connolly 1991 [Southwest Oregon]; Sanger 1970).  While the new Plains Anthropologist paper provides an introduction to the technology, it is not an exhaustive review, and as other examples have been identified we have endeavored to share those occurrences, e.g., Lee et al. (2015). 

This post shares a microcore-like artifact that was recovered by Metcalf Archaeological Consultants, Inc., during a project for the Bureau of Reclamation in northwest Wyoming.  The core may also have been used as a scraper and is made on a material consistent with high quality white variants of Spanish Point chert from the northern Bighorn Mountains (Lee and Lee 2016).  The figure below shows a conical microcore from 24MA230, an archaeological site in south-central Montana (Lee et al. 2015), alongside the microcore-like artifact from 48CK31.



For purposes of the studies reported in Lee et al. (2016) and Lee et al. (2015) we selected cores exhibiting formal patterns of microlith removals, an activity that resulted in cores with a distinct morphology. Our criterion, arbitrarily defined as seven microlith flake scars, enabled us to distinguish the microcores from nodules that had fewer microlith removals. These result in cores with a microcore-like appearance, but that might have been part of a different range of behavioral activities.  While the core from 48CK31 falls into that category, it is worth noting that Kornfeld et al. (1995) identified similar artifacts at other sites in the region with these characteristics.  Microcore technology is seemingly uncommon and easily overlooked, but demonstrated occurrences suggest it deserves further investigation.  At present, one of the take-homes regarding this technology is the distinction between formally produced microblades of the Late Paleoindian period and the less patterned, informal microliths of the Late Archaic and Late Prehistoric.

We thank Reclamation archaeologist Renee Boen for her support of our work.





Connolly, Thomas .J.

1991  The Standley Site (35DO182): Investigations into the Prehistory of Camas Valley, Southwest Oregon. Anthropological Papers No. 43. University of Oregon.


Deaver, Ken and Sherri Deaver

1984       Archaeological Site Testing and Evaluation in the Bear Trap Canyon of Madison County, Montana.  Report prepared for Bureau of Land Management, Butte District, Butte, Montana.


Kornfeld, Marcel, George C. Frison, and Mary Lou Larson (editors)

1995       Keyhole Reservoir Archeology, Glimpses of the Past from Northeast Wyoming. Occasional Papers on Wyoming Archeology, No. 5. Laramie, Wyoming.


Lee, Craig M., Michael Neeley, Mark Mitchell, Marcel Kornfeld and Crae O’Conner

2016       Microcores and Microliths in High Plains and Rocky Mountain Front Lithic Assemblages.  Plains Anthropologist. Published online, print version to come.


Lee, Craig M., Michael Neeley, Mark Mitchell, Marcel Kornfeld

2015       Microcores in Idaho? Idaho Professional Archaeological Council (IPAC) News 8(2):10-11.


Lee, Craig M. and Jennifer B. Lee

2016       National Register of Historic Places Evaluation of Sites 48CK6, 48CK31, 48CK32, and 48CK1278, Keyhole Reservoir, Crook County, Wyoming.  Bureau of Reclamation, Great Plains Region, Dakotas Area Office, Rapid City, South Dakota


Roll, Tom E., and Michael P. Neeley

2014       The Camp Baker Quarry (24ME467): 2001. Bureau of Land Management Cultural Resources Series No. 6.  Montana State Office, Billings, Montana.


Sanger, David

1970       Mid-latitude Core and Blade Traditions. Arctic Anthropology 7(2):106-114.


Wilson, Michael C., John Visser, and Martin P. R. Magne

2011       Microblade Cores from the Northwestern Plains at High River, Alberta, Canada. Plains Anthropologist 56(217):23-36.