Blue St!
Trailhead Pro 45L Adventure Backpack
Built for the long haul. The Trailhead Pro 45L is our most versatile pack yet. It's made for weekend backpacking trips, multi-day hut-to-hut routes, and one-bag international travel. We spent three years testing prototypes across the Rockies, the Scottish Highlands, and the Patagonian steppe to get every strap, pocket, and seam right.
Whether you're scrambling up a granite ridge or sprinting through a terminal to catch a connecting flight, the Trailhead Pro carries the load comfortably and keeps your gear organized, dry, and easy to reach.
Why You'll Love It
- Adjustable torso length: fits torsos from 15" to 21" with a tool-free slider system.
- Weatherproof shell: 420D recycled ripstop nylon with a PFC-free DWR coating.
- Clamshell main compartment: opens fully like a suitcase for easy packing.
- Ventilated back panel: suspended mesh keeps air moving on hot climbs.
- Hydration compatible: internal sleeve fits reservoirs up to 3L.
- Carry-on friendly: meets most airline carry-on size limits when compressed.
- Lifetime warranty: we stand behind every stitch.
Designed for Real Adventures
Most packs make you choose between a technical hiking pack and a travel bag. The Trailhead Pro is both. Stowable hip belt wings and a zip-away harness turn it from a trail-ready carry system into a clean, snag-free duffel in under 30 seconds.
The frame uses a single aluminum stay that transfers weight to your hips without the bulk of a traditional internal frame. It's stiff enough to carry 35 lbs (16 kg) comfortably, but light enough that the whole pack weighs only 2 lbs 14 oz (1.3 kg).
“I took the Trailhead Pro on a 9-day trek through the Dolomites and never once wished I'd brought something else. The hip belt pockets alone are worth it.”
— Marisol K., verified buyer
Organization That Makes Sense
Every pocket has a purpose. Here's how the storage is laid out:
- Main compartment (32L): clamshell zip with internal compression straps.
- Front stash pocket (5L): stretch mesh for wet layers, sandals, or a rain fly.
- Laptop sleeve: padded and suspended, fits laptops up to 16".
- Top lid pocket (3L): for snacks, headlamp, sunscreen, and maps.
- Hip belt pockets (2 Ă— 0.5L): big enough for a large smartphone.
- Side water bottle pockets: angled so you can reach them while walking.
- Hidden security pocket: against your back, for your passport and cards.
- Sunglasses quick-stow: soft-lined loop on the shoulder strap.
Technical Specifications
| Specification | Size S/M | Size M/L |
|---|---|---|
| Volume | 42L | 45L |
| Weight | 2 lbs 11 oz (1.22 kg) | 2 lbs 14 oz (1.30 kg) |
| Dimensions | 21" Ă— 13" Ă— 9" | 22" Ă— 14" Ă— 9" |
| Torso range | 15"–18" | 18"–21" |
| Hip belt range | 26"–40" | 30"–46" |
| Max recommended load | 35 lbs (16 kg) | |
Materials & Sustainability
We think good gear shouldn't cost the planet. The Trailhead Pro uses:
- 100% recycled 420D ripstop nylon body fabric
- Recycled 210D nylon lining
- PFC-free durable water repellent (DWR) finish
- YKK® AquaGuard® zippers on exterior pockets
- Bluesign® approved materials throughout
- Plastic-free, recyclable packaging
Every pack is made in a Fair Trade Certified™ factory, and 1% of every sale goes to trail conservation groups through 1% for the Planet.
Comfort, Dialed In
The shoulder straps are S-curved and lined with dual-density foam that molds to your body over time. The sternum strap slides along a full-length rail, so it sits right no matter your build. Load lifters pull the weight close to your center of gravity, and the hip belt pivots with your stride to cut down on chafing on long days.
Women's-specific and men's-specific harness options are available. Both use the same pack body and differ only in strap geometry and hip belt angle. Not sure which to choose? Check out our Fit Guide or chat with our gear experts.
What's in the Box
- 1 Ă— Trailhead Pro 45L Backpack
- 1 Ă— Removable rain cover (stored in base pocket)
- 1 Ă— Detachable sling bag (2L) for day trips
- 2 Ă— Accessory straps
- 1 Ă— Care & warranty card
Care Instructions
To keep your pack in top shape:
- Empty all pockets and shake out any debris.
- Spot clean with a soft brush, mild soap, and lukewarm water.
- Do not machine wash, tumble dry, or dry clean.
- Hang to air dry away from direct sunlight.
- Reapply DWR treatment once a season, or as needed.
Frequently Asked Questions
Is the Trailhead Pro waterproof?
The fabric is highly water resistant thanks to the DWR coating, and the seams are taped at critical points. For sustained heavy rain, use the included rain cover.
Will it fit in an overhead bin?
Yes. When compressed, the pack fits within the carry-on limits of most major airlines (22" Ă— 14" Ă— 9"). Some budget carriers have stricter rules, so check with your airline before you fly.
Can I use it with trekking poles?
Absolutely. There are dedicated trekking pole loops on the left side and a stow-on-the-go bungee system so you can stash poles without taking the pack off.
What does the lifetime warranty cover?
Our warranty covers defects in materials and workmanship for the life of the product. Normal wear and tear, accidents, and misuse aren't covered, but our repair team can usually fix those for a small fee.
Shipping & Returns
Free standard shipping on orders over $75 within the contiguous US. Orders placed before 2Â PM ET ship the same business day.
Not in love? Return unused items within 60 days for a full refund. Used it on the trail and it isn't working for you? We'll still take it back within 30 days through our Trail-Tested Guarantee.
Pack once. Go anywhere.
The Trailhead Pro 45L: your last backpack.