The site's pre-Clovis occupation is supported by numerous lines of evidence including optically stimulated luminescence (OSL) dates ranging from 13,200-15,500 before present, undisturbed stratigraphy, and an extensive stone tool assemblage.

[2] OSL is a technique that analyzes light energy trapped in sediment particles to identify the last time the soil was exposed to sunlight.

[5] Beginning in the mid 20th century the consensus among archaeologists was that the first human colonizers of the New World were the Clovis people who migrated from Siberia across Beringia and down into the Americas from 13,200-12,800 BP.

It is believed that Clovis peoples with their characteristic fluted lanceolate-shaped points quickly spread throughout all of North and South America.

This theory for the colonization of the New World is known as the "Clovis First" model and has recently come under question by the discovery and acceptance of the Monte Verde, Chile site which has radio-carbon dates going back to 14,600 BP calibrated.

The discovery of the Buttermilk Creek complex has helped archaeologists further their quest to identify who the first humans were to reach the New World, when and how they arrived here and where their point of origin was.

The findings of the excavations were analyzed and interpreted using a holistic approach that featured researchers from many different fields including: Steven L. Forman and James Pierson who are experts in OSL dating; Lee C. Nordt, Steven G. Driese, Joshua M. Feinberg, and Anna Lindquist-who are all geologists or geophysicists; Charles T. Hallmark who is a soil scientist; and archaeologists including Michael R. Waters, Thomas A. Jennings, Joshua L. Keene, Jessi Halligan, and Michael B.

Lanceolate stemmed projectile points are found throughout this layer (OSL dated from around 15,500 to 13,500 years ago), beneath the Clovis horizon.

[2] The Buttermilk Creek complex artifact assemblage is much larger and more varied than other North American sites advanced as having a pre-Clovis component.

The 4 artifacts that were analyzed for use-wear show polish and striations indicative of cutting, grooving, or incising of a hard material such as bone, wood, or antler.

The debitage found in all 3 horizons is characteristic of late stage lithic reduction, which shows that the site was used for the same purpose by each set of peoples.

The integrity of the deposit, affected as it is by its vertisol soils, which undergo disturbance during opening and closing of cracks during moisture changes, has been questioned.

Also, the very large errors and the researchers' assumptions about water content of the strata over thousands of years in regard to the OSL age estimates, have caused multiple critics to question the dating of the site and that of others of the complex nearby, such as Gault.