For winter footwear, I second the recommendation for brain tanned moccasins. Specifically, sinew stitched. Add a crepe rubber sole and a felted alpaca liner and you've got something very warm, durable, incredibly comfortable and mighty Husp-y, I'd say.
Mine are in the Kainai tradition, leather and pattern-wise anyway. (We also do a urine-cure on the leather, which I don't always mention conversationally when people comment on the colour of Blackfoot natural white hides - but this is Permies, so there you have it. Pee.)
The crepe rubber could definitely be argued against in term of sustainability/regionality these days, considering how far it would have to travel now but, I inherited a couple of very old sheets of it. Last winter was my first experiment with felted alpaca fibre, and while certainly not "traditional", definitely 'toasty'. I tried alpaca because wool of all persuasions -even merino- makes me squirm in an itchily intolerable way. For whatever reason, alpaca does not. A fibre artist friend suggested it could have to do with a lack of lanolin. (In the alpaca. Not me.)
Two caveats with this footwear; sneakiness and grippiness. Factors: high.
They are so quiet outdoors, it is easy to terrify.
They are so adherent indoors, it is easy to stick.
...And squeak, squalch, and peel away with other gummy-type sounds. That mostly seems to happen with commercial flooring though so, while embarrassing for me at the flea market, not likely problematic for you on the range.
A local fibre arts guild could help track down someone to create felt from regional animals. Of the different tribes down your way you'd likely be able to find someone who crafts moccasins in one 'old' way or another.