The Encyclopedia of Oklahoma History and Culture

SUMMERS SITE.

From 5000 B.C. to 1200 B.C. the Altithermal, a drought of a severity unimaginable to its modern inhabitants, beset the Great Plains. The southwestern Great Plains turned from grassland to desert, and there was very little evidence of human habitation of the region during this time. This Altithermal virtually depopulated western Oklahoma and adjacent parts of Texas for several thousand years.

The Summers Site, in Greer County, appears to be the earliest excavated post-Altithermal archaeological site on the southwestern Great Plains. A radiocarbon assay of woody charcoal from a rock-filled cooking pit, also containing bison bone, has been dated to about 2,900 years ago (circa 900 B.C.). Current geoarchaeological research in western Oklahoma has indicated that the canyon systems began rapidly filling with sediment about 1200 B.C. in response to increasing rainfall, so the radiocarbon date from Summers has been considered reasonable from that perspective.

However, chipped stone artifacts from Summers suggest a much later date for the site. Corner-notched dart points, bifacial knives and choppers, and simple, unifacial flake tools made of Ogallala quartzite, Alibates agate, and various cherts from Ogallala Formation gravels have been typical of Late Archaic cultures of the region.

Radiocarbon dates from well-documented Late Archaic sites in western Oklahoma and the Texas Panhandle indicated that people did not return to the area for a lengthy period after the Altithermal. Although there has been limited evidence of Late Archaic people killing bison at the Certain site as early as 400–350 B.C., most dates from southern plains Late Archaic sites fall in the time span 1–400 A.D. It is likely that the Summers Site actually dates around the time of the Christian era or slightly later.

John Peter Thurmond