Ancient Footprints Persevered in the Great Salt Lake Desert

Ancient footprints are preserved in the Great Salt Lake Desert.  An excavated footprint is in the foreground but you can also see unexcavated footprints (which appear like darker shadows in this image) in the background. July 2022.

Hill AFB recently announced a unique archaeological site in the GSL Desert on their South Bombing Range.

Named the Trackways Site, it consists of several tracks of human footprints likely dating to about 12,000 years ago.

Thousands of Paleo-age archaeological sites have been found in this area of the GSL Desert, including the famed Wishbone Site with a radiocarbon date on a fire hearth of 12,300 years ago. Although the finding of intact human footprints is surprising, it is in line with previous discoveries in the area.

The archaeologists are being cautiously optimistic about the authenticity of the find, citing more research is required.

I visited this site a short time before the official press release; I went in skeptical and left fairly convinced of its human antiquity. The stratigraphy is what ultimately convinced me.

Nowadays, that area of the GSL Desert is a wide-open alkali flat almost void of all flora and fauna, which means most people avoided it for most of the last 10,000 years.

The GSL Desert was once the bottom of Lake Bonneville in which fine silts were deposited on the lake floor. Then, during the waning years of Lake Bonneville, the area became a vast wetland fed by overflow water through the Old River Bed and springs, thus creating a vast wetland known as the Old River Bed (ORB) Delta.

The type of sediment deposited during each of these stages also changed from the fine silts of a deep lake to the sands and gravels transported by faster flowing streams.

These unexcavated footprints are inverted sand-filled prints. The sand erodes at a slower rate than the surrounding Lake Bonneville silt, These footprints are a part of a longer footprint trackway. July 2022.

The footprints themselves appear to have been formed when people walked in the shallow water of this ancient wetland. Their feet sunk through the sand into the underlayer of fine Bonneville silts, which were then filled in with the overlayer of sand after the foot was removed. Consequently, the footprints were preserved as sand-filled imprints, some of which are now exposed as inverted sand prints surrounded by alkali flats.

Here is the link to the original Hill AFB press release.