And yet the Navajo Nation bordering both of them has fairly strict gun registries. Both of those are yet different than the situation in Alberta (more similar to TX), and YT more resembles Alaskan gun culture.

They're obviously not related by immigration group either. The Hopi descend from early first nations. The Navajo descend from the athabascan migrations. Yukon comes from Canadian and British gold rush populations. Alberta comes from various prairie settler efforts, including Ukrainian Canadians. The Mormons were their own settlement group in Mexico that went to war with many of the (now-) surrounding indigenous nations. Etc.

And this is just one "American nation". The same basic issue exists in all of them.

> And yet the Navajo Nation bordering both of them has fairly strict gun registries.

The fact there are political differences by region is not a defining factor, or the regions would look very different. The fact it is a cultural topic at all, looks to be one common factor. I feel like I'm talking in circles now.

Regardless, I really don't understand this sort of hair splitting. My imagination isn't that expansive, yet I can understand how these regions might have been determined in many cases. Asking the authors might get answers to these kinds of questions.