Stay comfortable on cooler-weather adventures in the Smartwool Intraknit Thermal Merino men's 3/4-length base layer bottoms, which have a performance-enhancing design and a shorter, versatile length.

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The winter-ready pants you need to perform all season, the men's Smartwool Intraknit Thermal Merino Base Layer 3/4 Bottoms use merino wool to help keep you comfortable on every cold-weather outing.

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Built to flex and follow you like a shadow, the men's Smartwool Intraknit Thermal Merino base layer bottoms put warmth first, while 3D knit mesh ventilation helps keep you dry and comfortable.

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Make your first layer a comfortable one with the men's Picture Organic Clothing Lhotse base layer pants. They feature chafe-free seams and a nonirritating elastic waist band.

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Fend off the chill and stay out longer in the men's Helly Hansen Lifa Merino Midweight base layer pants. Built for winter fun, they blend merino wool with technical fabric to keep you cozy and warm.

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These REI lightweight base layer bottoms are designed to keep you warm and wick away moisture during high-performance outdoor activities when the temperature starts to drop.

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From morning's first frosty steps to midday sweat and exhilaration, the men's REI Co-op lightweight base layer bottoms wick and breathe to keep you comfortable all the way.

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The men's REI Co-op lightweight base layer bottoms wick and breathe to keep you comfortable from the first cold steps of morning to sweaty exhilaration on the trail hours later.

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When it comes to base layers, basic is better. The men's Lole Logan base layer bottoms are perfect under your gear for outdoor training or activities, or for everyday life.

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Soft, breathable and naturally odor resistant, the ultrafine merino wool of the men's REI Co-op Merino 185 base layer bottoms is just as beloved while sweating on the trail as sleeping in the tent.

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Soft, breathable and naturally odor resistant, the ultrafine merino wool of the men's REI Co-op Merino 185 base layer bottoms is beloved for sweating on the trail—and just sleeping!

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An ideal performance layer, the men's REI Co-op Midweight Base Layer Bottoms boast a smooth face and low-bulk seams for easy layering and a brushed back for added warmth and comfort.

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Stay dry, warm and stoked all day with the men's Burton Midweight Base Layer pants, which give you moisture-wicking fabric with a cottonlike feel and a plush waistband.

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Shred to your heart's content with the comfort of these men's Midweight X base layer bottoms. They're your quiver-of-one, serving up quick-drying, stink-free warmth for long days on the mountain.

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