>>2671417Nokian Footwear still sells boots made with real natural rubber.
>>2671165Their Naali-model is the civilian counterpart of what the Finnish Defence Forces use. I also have a pair and I love them. (I am at work now so can't show a pic of my own, but here is a picture from the manufacturers website)
For winter they issue these winter rubber boots with removable felt liners. For winter warfare exercises they were a must have, essentially an only way to keep your toes warm in the cold weather while doing soldier stuff.
The trick is to have one (or two) spare pair of felt liners and spare socks in your backpack. Change in to dry socks regurarly and then and then check how your felt liners are doing, change in to dry ones if needed. In order to ory out the liners, you hang them in the squad tent (which is heated with a wood burner stove) when you go sleep in there. Those winter rubber boots also have an inbuilt groove for cross country ski bindings, which allows the soldiers to use skis relatively easily and quickly during their missions. That makes the troops more mobile in the winter season than when travelling on foot or on snowshoes.