Merino Wool Base Layers
(207 products)- REI Co-opHeavyweight Merino Long-Sleeve Base Layer Crew Top - Men's$69.93 - $99.95Underwear Weight:HeavyweightSize Type:Regular, Big, Tall
- REI Co-opHeavyweight Merino Base Layer Bottoms - Women's$69.93 - $99.95Underwear Weight:HeavyweightSize Type:Regular, Plus
- REI Co-opHeavyweight Merino Base Layer Bottoms - Men'sTop Rated$69.93 - $99.95Underwear Weight:HeavyweightSize Type:Regular, Big, Tall
- SmartwoolClassic Thermal Merino Quarter-Zip Base Layer Top - Women'sTop Rated$130.00Underwear Weight:MidweightSize Type:Regular, Plus
- SmartwoolClassic Thermal Merino Base Layer Bottoms - Men'sTop Rated$125.00Underwear Weight:MidweightSize Type:Regular, Big
- SmartwoolClassic Thermal Merino Quarter-Zip Base Layer Top - Men'sTop Rated$130.00Underwear Weight:MidweightSize Type:Regular, Big
- SmartwoolClassic Thermal Merino Crew Base Layer Top - Men'sTop Rated$125.00Underwear Weight:MidweightSize Type:Regular, Big
- REI Co-opHeavyweight Merino Long-Sleeve Base Layer Crew Top - Women's$69.93 - $99.95Underwear Weight:HeavyweightSize Type:Regular, Plus
- REI Co-opHeavyweight Merino Base Layer Half-Zip Top - Women'sTop Rated$72.93 - $104.95Underwear Weight:HeavyweightSize Type:Regular, Plus
- SmartwoolClassic Thermal Merino Base Layer Bottoms - Women's$125.00Underwear Weight:MidweightSize Type:Regular
- SmartwoolClassic Thermal Merino Crew Base Layer Top - Women'sTop Rated$125.00Underwear Weight:MidweightSize Type:Regular, Plus
- tasc PerformanceElevation Merino Base Layer Bottoms - Men's$34.73 - $54.73Save 30% - 56%compared to  $79.00Underwear Weight:LightweightSize Type:Regular, BigREI OUTLET
- SmartwoolClassic All-Season Merino Long-Sleeve Base Layer Top - Men'sTop Rated$66.93 - $100.00Underwear Weight:LightweightSize Type:Regular, Big
- REI Co-opMerino 185 Base Layer Bottoms - Men's$55.93 - $79.95Underwear Weight:LightweightSize Type:Regular, Big
- tasc PerformanceElevation Merino T-Shirt - Men's$34.73 - $54.73Save 30% - 56%compared to  $79.00Underwear Weight:LightweightSize Type:Regular, BigREI OUTLET
- IcebreakerMerino 200 Oasis Long-Sleeve Crewe Thermal Top - Men'sTop Rated$69.93 - $120.00Underwear Weight:MidweightSize Type:Regular, Big
- tasc PerformanceElevation Merino T-Shirt - Women's$54.73Save 30%compared to  $79.00Underwear Weight:LightweightSize Type:Regular, PlusREI OUTLET
- REI Co-opMerino 185 Long-Sleeve Base Layer Top - Women's$79.95Underwear Weight:LightweightSize Type:Regular
- REI Co-opMerino 185 Base Layer Bottoms - Women's$79.95Underwear Weight:LightweightSize Type:Regular
- tasc PerformanceElevation Merino Base Layer Bottoms - Women's$54.73Save 30%compared to  $79.00Underwear Weight:LightweightSize Type:Regular, PlusREI OUTLET
Get $130 in value
$30 in card rewards are yours when approved for the REI Co-op Mastercard by Mar 9. Plus, you can earn a $100 REI gift card after your first purchase. Terms apply.
Apply now- REI Co-opMerino 185 Long-Sleeve Base Layer Top - Men'sTop Rated$79.95Underwear Weight:LightweightSize Type:Regular, Big
- REI Co-opHeavyweight Merino Base Layer Half-Zip Top - Men's$72.93 - $104.95Underwear Weight:HeavyweightSize Type:Regular, Big, Tall
- REI Co-opMerino 185 Long-Sleeve Half-Zip Base Layer Top - Men'sTop Rated$62.93 - $89.95Underwear Weight:LightweightSize Type:Regular, Big
- IcebreakerMerino 200 Oasis Long-Sleeve Crewe Thermal Top - Women'sTop Rated$69.93 - $120.00Underwear Weight:MidweightSize Type:Regular, Plus
- Kari TraaKlara High-Waisted Base Layer Pants - Women's$62.73 - $66.73Save 25% - 30%compared to  $90.00Underwear Weight:LightweightSize Type:RegularREI OUTLET
- Kari TraaRose Half-Zip Base Layer Top - Women's$97.93 - $140.00Underwear Weight:MidweightSize Type:Plus, Regular
- Kari TraaRose High-Waisted Base Layer Pants - Women'sTop Rated$90.93 - $120.00Underwear Weight:LightweightSize Type:Regular
- Icebreaker260 Tech High-Rise Base Layer Leggings - Women's$125.00Underwear Weight:MidweightSize Type:Regular
- SmartwoolClassic All-Season Merino Long-Sleeve Base Layer Top - Women's$100.00Underwear Weight:LightweightSize Type:Regular, Plus
- Kari TraaEdith Half-Zip Base Layer Top - Women's$81.73Save 25%compared to  $110.00Underwear Weight:MidweightSize Type:RegularREI OUTLET

















































































































































