I was lucky enough to get paid to do field work in south west Montana in the 80's. I got to spend quite a bit of time in the backcountry there and my memories are very positive. But as I try to remember details (so as to prep for my upcomming Wind River trip), I am remembering tons of mosquitos, and even worse on occasion the deer and horse flys. Those things would bite through multiple layers of shirts as well as blue jeans. So my question is; are the newer synthetic materials tight enough to keep these things from taking chunks out of me? Back in the 80's it was all cotton or wool.