Footprints dating back 12,000 years have been found in salt flats at Hill Air Force Base in Utah.

More evidence showing that human beings had spread well into the continent much earlier than had only recently been supposed.

The area was, at the time, a wetland. The footprints appear to be those of women and children.

23,000 year old human footprints found in New Mexico.

And that's a big deal.

It's a big deal, as it pushes the human presence in North America way back beyond what had been previously suspected in a spectacular example of Holscher's First Law of History.

And if humans were in New Mexico 23,000 years ago, so far back that the Ice Age land bridge isn't a very good explanation for how humans got here from Asia, it means they arrived at least some time prior to that. After all, you can't walk from Point Barrow to New Mexico in a day.