I think the main difference in our respective opinions is one of time scale.

You seem to stick with the paper in your focus on long time periods representing several hundred generations and the things that could limit or prevent human arrival or presence at the location during the time period proposed.

I am focusing on things that could plausibly happen to a nomadic group within a single human lifespan. It doesn't matter where on the time line one would place the nomadic group, these achievements are possible and the dating of these footprints using three complementary methods which all yield similar dates strongly suggest that people did in fact make it to New Mexico by that early date.

We will never know how they arrived unless we can find new sites to confirm a likely path of travel. They may have followed the coastline south in boats stopping wherever they found shelter and food. They may have used sleds or travois to move their worldly possessions cross-country over any terrain whether ice-covered, tundra, forested, or open plain. We know that they were adaptable and they were closely in tune with their environments, with a deep understanding of seasons, wildlife, plants, and weather. They had to be just to be able to make the trip to Beringia or to eastern Asia. Their knowledge had to be encyclopedic and like most knowledge in ancient cultures was almost entirely passed generation to generation orally. There are still cultures who pass these traditions orally, keeping alive the old knowledge and skills. [0]

We know nothing about the normal divisions of labor within a group but we do know from direct evidence that people did in fact make the trip overcoming all of the challenges they found along the way. Where they went after leaving those tracks is anyone's guess and is up for future discovery, just like the path they took to get there.

I read the paper that you linked. I appreciate the link.

I agree with your final sentence:

>It's pretty clear at this point that the coastal route happened eventually, but we need a lot more data to put together a sensible theory that can reconcile these outliers.

Though you and I reach different conclusions we can agree that a lot more research and discovery is needed to understand how these people arrived in present-day New Mexico that long ago.

I found on reading it that the paper did not discount the possibility that people followed the coast south or that they traveled overland for the entire journey into the interior of the North American continent during the time period when these tracks were probably made, LGM. In fact in the sections where they addressed this question they hold open the possibility that humans could have taken advantage of seasonal variations in sea currents, glacial meltwater flows, local warming of land routes, etc to make the trip.

Their data does not have a high enough resolution to answer the question of whether anyone attempted the journey successfully or unsuccessfully. Their resolution is on the scale of millenia whereas one would need seasonal data for insight into the answer. I guarantee that the humans that left those footprints had a detailed knowledge of seasonal variations in local conditions and they took full advantage of that in order to secure their survival.

I look forward to reading more about efforts to nail down when and how early humans made the journey into North America and to find out how they fared on arrival. I'm a geoscientist but I have always loved archaeology.

[0] https://hakaimagazine.com/features/with-old-traditions-and-n...