Whether you're hitting the trail for a summer day hike or gearing up for a multi-day fall backpacking adventure, the Smartwool Classic All-Season Merino Base Layer delivers the perfect foundation for your layering system. This women's long sleeve crew combines the natural comfort and odor-resistance of responsibly sourced Merino wool with innovative Core Spun technology, wrapping that luxurious wool around a recycled nylon core for enhanced durability without sacrificing next-to-skin softness. The raglan sleeve construction eliminates shoulder seams entirely, so you can shoulder your pack all day without chafing or pressure points, while the slim fit contours naturally to your body for seamless layering. From alpine starts to sweaty ascents, this versatile base layer adapts to changing conditions while keeping you comfortable mile after mile.