The higher the elevation, the cooler the weather, so we reach for the Outdoor Research Alpine Onset Merino 150 Bottom for our all-season summits. These lightweight merino wool bottoms offer just-right insulation, wicking moisture management, and natural anti-odor tech for year-round adventuring. Updated fabric is extra durable and stretchy, thanks to polyester and Lycra fibers, and a gusseted crotch increases our range of motion further to help with scrambles and skin track ascents. Flat-lock seams make the next-to-skin fit chafe-free to keep us active throughout the seasons.