Lowa "Sheephunters". I hunted dalls sheep in Alaska a few years back in a pair of these. We spent a lot of time in "scree" and my boots survived with just a few surface scratches. My guides new pair of Vasq boots looked like they had been run through a shredder. Since then, these boots have survived several years of elk hunting and guiding in some very rough rocky country in NM and are no worse for wear.
They are lightly insulated, and the only downside is they are fairly heavy. However, if you want a pair of boots that will not let you down in rough country I don't think you have to look any further.