Layers help-
A given day of bow hunting in MT starts off cool/cold, then you start hiking straight up hill in the dark and sweat your @$$ off, then you sit in the cold for a bit and freeze, then the sun comes up and its hot, then the sun goes down and you are cold again... When I lived there, I had no complaints about Cabela's microtex pants, a lightweight long-sleeved shirt (mine was that sage brush looking camo pattern and that seemed okay in SW MT, I'm part color blind, but gray- and brown-based tones seem appropriate for the woods there to my eye), a lightweight fleece pullover, and a lightweight packable rain jacket and a small synthetic down jacket in my pack just in case.
It can be downright cold late in the archery season, so more layers are obviously necessary then, but the above combo served me well for most Septembers anyway.