Smartwool Men's Classic Thermal Merino Baselayer Bottoms

Say goodbye to bulk that bunches up in your boots

Keep your lower half completely insulated and ready for action with the Smartwool Men's Classic Thermal Merino Baselayer Bottoms. Engineered as one of the heaviest and most protective cold-weather layers available, these high-performance long johns are constructed from 100% responsibly sourced Merino wool using an advanced interlock knit that maximizes heat retention while allowing skin to breathe. The body-skimming slim fit is tailored with a smooth, merino-lined elastic waistband and a traditional functional fly. Designed with flatlock seams throughout, these bottoms eliminate high-friction rubbing when layered beneath ski pants, insulated bibs, or heavy denim. Thanks to the natural moisture-wicking and odor-resistant superpowers of pure Merino wool, you stay dry, fresh, and remarkably warm from early morning backcountry ascents to the very last run of the day.