Congratulations, nice buck! I would echo what others have said. I think in Montana most people would shoot a 150" buck, I also think most decent 4 points are a lot closer to 140"; 150" is a relatively big buck. 160" is big here, and as illustrated by greenhorn 170" is a very big deer. I saw a 170 class deer this year and it dwarfed the modest 22"' 4 point that it stood by, which was the sort of normal mature buck one would expect in Montana.
If you want to shot a deer I think you better shoot a 150" buck if you see one.
That's a great deer. Congratulations. I guess I missed that this was in an unlimited area. A while back there was a thread about unlimited mule deer buck areas. I grew up hunting an unlimited area, and I threw up some pictures of deer that came out of there. Yours would be a great deer in the unlimited district I grew up hunting.