Katmai Heavyweight Men's 100% Merino Wool Bottom
Named for Mt. Katmai in Alaska's Katmai National Park—home to the Valley of Ten Thousand Smokes—these heavyweight base layer bottoms are built for the most extreme cold. The 400 g/m² construction delivers serious warmth when temperatures plunge below zero, while 100% merino wool keeps you comfortable with natural temperature regulation, moisture wicking, and odor resistance. You'll barely notice these long johns as they fit snug against your skin with no itch or irritation. When you need to stay warm in the harshest conditions, the Katmai is the garment for you.
Why You'll Love These Base Layer Pants
- 100% merino wool for natural warmth, moisture wicking, and odor resistance
- Heavyweight 400 g/m² interlock knit—our warmest base layer
- 18.5-micron fibers feel soft against skin with no itch
- Covered waistband keeps merino wool next to your skin
- Gusseted crotch reduces stress and improves mobility
- Ribbed ankle cuffs stay in place and allow easy layering
- Flatlock seams prevent chafing during all-day wear
- UPF 50+ sun protection
Size & Fit
Regular fit with room to breathe but not baggy. Available in XS-4XL. Runs true to size. Reference model: 5'10", 150 lbs wears size Medium.
- XS: Waist 24-27", Inseam 25-27"
- S: Waist 28-30", Inseam 28-30"
- M: Waist 31-33", Inseam 29-32"
- L: Waist 34-36", Inseam 32-34"
- XL: Waist 37-40", Inseam 32-35"
- XXL: Waist 41-44", Inseam 34-35"
- XXXL: Waist 45-49", Inseam 34-36"
- 4X: Waist 49-52", Inseam 34-36"
Care Instructions
Turn inside out and machine wash cold on gentle cycle with mild or wool-specific detergent like M33 Nikwax Wool Wash. Tumble dry on low heat. Store in an airtight container when not in use for extended periods. Never use fabric softener or bleach.
Complete Your Look
Pair with a Minus 33 heavyweight crew top for a complete extreme-cold base layer system. Explore our full Merino Wool Collection from Minus 33, a 5th-generation New Hampshire family business with over a century of textile expertise.
Katmai Heavyweight Men's 100% Merino Wool Bottom
Named for Mt. Katmai in Alaska's Katmai National Park—home to the Valley of Ten Thousand Smokes—these heavyweight base layer bottoms are built for the most extreme cold. The 400 g/m² construction delivers serious warmth when temperatures plunge below zero, while 100% merino wool keeps you comfortable with natural temperature regulation, moisture wicking, and odor resistance. You'll barely notice these long johns as they fit snug against your skin with no itch or irritation. When you need to stay warm in the harshest conditions, the Katmai is the garment for you.
Why You'll Love These Base Layer Pants
- 100% merino wool for natural warmth, moisture wicking, and odor resistance
- Heavyweight 400 g/m² interlock knit—our warmest base layer
- 18.5-micron fibers feel soft against skin with no itch
- Covered waistband keeps merino wool next to your skin
- Gusseted crotch reduces stress and improves mobility
- Ribbed ankle cuffs stay in place and allow easy layering
- Flatlock seams prevent chafing during all-day wear
- UPF 50+ sun protection
Size & Fit
Regular fit with room to breathe but not baggy. Available in XS-4XL. Runs true to size. Reference model: 5'10", 150 lbs wears size Medium.
- XS: Waist 24-27", Inseam 25-27"
- S: Waist 28-30", Inseam 28-30"
- M: Waist 31-33", Inseam 29-32"
- L: Waist 34-36", Inseam 32-34"
- XL: Waist 37-40", Inseam 32-35"
- XXL: Waist 41-44", Inseam 34-35"
- XXXL: Waist 45-49", Inseam 34-36"
- 4X: Waist 49-52", Inseam 34-36"
Care Instructions
Turn inside out and machine wash cold on gentle cycle with mild or wool-specific detergent like M33 Nikwax Wool Wash. Tumble dry on low heat. Store in an airtight container when not in use for extended periods. Never use fabric softener or bleach.
Complete Your Look
Pair with a Minus 33 heavyweight crew top for a complete extreme-cold base layer system. Explore our full Merino Wool Collection from Minus 33, a 5th-generation New Hampshire family business with over a century of textile expertise.