Archaeologists have stumbled upon 88 ancient footprints dating back about 12,000 years in the Utah desert.
The "ghost footprints," which were discovered last month at Hill Air Force Base in Utah's Great Salt Lake Desert, get their name because they can only be seen after it rains, when the prints fill up with water, and vanish as they dry out in the sun.
The human footprints were found in the alkali flats on the Utah Test and Training Range. The 5,000-acre archaeological survey, which employs the use of non-invasive equipment such as magnetometers and ground-penetrating radar, holds other artifacts dating back to the Ice Age.
"Based on excavations of several prints, we've found evidence of adults with children from about 5 to 12 years of age that were leaving bare footprints," said Daron Duke, principal investigator with Far Western Anthropological Research Group. "People appear to have been walking in shallow water, the sand rapidly infilling their print behind them -- much as you might experience on a beach -- but under the sand was a layer of mud that kept the print intact after infilling."
The ancient footprints discovered in Utah are only the second found in the United States. Pleistocene-Age human footprints, dating between 21,000 and 23,000 years ago, were identified last year in New Mexico's White Sands National Park.
12,000 years? That's about the right age to be Clovis culture.