That's like 90% of rural America though. I've lived in various rural areas and they were invariably majority very pro gun, at least in the south and western USA. Northeast is more of a hodge podge on 2nd amendment though, and you have to go deeper into rural areas for stronger support.

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.