Online Rock Art Lectures

March 15, 2025  (Note that this lecture will be on the third Saturday in March rather than our typical second Saturday.)

Geoarchaeology and Rock Art: the Middle Fork of the Powder River, Wyoming - Julie Francis  Register

Authors: Julie Francis, Larry Loendorf, William P. Eckerle,  Spencer Pelton, and Mark Willis.

Occasionally, rock art researchers use the height of panels or elements above the present ground surface as a general indicator of relative age.  Images that are now mostly inaccessible due to erosional processes are presumed to be older than images accessible from the present ground surface.  Such relative age estimates assume that ancient artists did not use some type of ladder or other, now-collapsed, access to reach cliff faces.

The Wold Rock Art District, situated on the Middle Fork of the Powder River (MFPR) at the juncture of the eastern base of the Bighorn Mountains and southwestern margin of the Powder River Basin, contains a complex mosaic of distinctive and unusual contemporaneous images.  Some of these are stranded nearly 4 meters above the present ground surface, while others are readily accessible from the present surface or nearly buried by surficial deposits at the base of panels.  To address this conundrum, we initiated geomorphology and soils studies to examine the alluvial chronology of this reach of the MFPR.

Coupled with data on superimpositions of different types of images and placement on panels, the geomorphology studies have proved critical to the construction of a relative chronology of the imagery, landscape reconstruction, and have enlightened our understanding of indigenous use of the district from Late Archaic to Protohistoric times.