i rode some of that same area a few years ago in UT (bryce, boulder, panguitch, burr trail), but was stuck to the slab due to a tire blowout on the burr trail that ended up my trip, and had me limping home. it's awesome to see the dirt side of things, and now with a proper steed... i'll have to go back!
i've got the 150 size of the k60 on my 990s, and even though it's been mostly slab since i got it on there, it seems to be wearing well... i've heard multiple other people mention that they also got horrible wear out of the 140 size of the k60, the 150 has a slightly different tread pattern, and is supposed to wear better.
dave6395 has a pic somewhere in the middle of his recent alaska rr of the 150w k60 rear after 4k miles, and it looks nothing like how yours turned out.
awesome report so far, keep it coming!