While we have merino wool at the top of mind for baselayers and socks, the Swisswool Piz Bial Jacket makes a pretty good case for using it in insulating layers as well. Since the jacket is insulated with wool, it effectively manages body temperature, so you stay at that just-right temperature, but it is also highly breathable, so you won't get too stuffy when you're hiking a steep section of trail, or making the long approach to the crag.

Ortovox Swisswool Piz Bial Jacket Women's - BNLDDXH46