Pre-order SALE - Save $100-$110
MSRP- from $650
MSRP- from $800
COMING SOON!
How does The Evolution SlumberSac
stack up against the rest of the Field?
| Feature | OWL — Evolution SlumberSac V1 | Traditional Mummy Bags | Standard Camping Quilts |
|---|---|---|---|
| Campsite Mobility | ✓ 100% Mobile (Total Freedom to Move/Walkable) | ✗ 0% Mobile (Immobile) | ✗ Restricted (Must untuck/wrap around body) |
| Campsite & Midnight Utility | ✓ Get up and leave tent WITHOUT exiting bag | ✗ Must unzip and fully exit bag/Return to a cold bag | ✗ Must fully detach and lose heat |
| Arm & Leg Openings | ✓ Integrated Sleeves and Zipped Footbox | ✗ None (Fully sealed inside confined bag) | ✗ None (Open bottom only) |
| Draft Protection | ✓ 360° Sealed Draft Guards | ✗ High (When fully zipped) | ✗ Low (Can experience side drafts) |
| Primary Camp Use | ✓ Midnight “Nature Calls,” morning coffee prep, grab gear effortlessly, side sleep easily, lightweight | ✗ Strict, stationary sleeping inside tent | ✗ Lightweight, flexible sleeping style |
| Overall Comfort Use | ✓ Sleep comfortably on your back, side, or even belly | ✗ Strict confinement, not good for claustrophobia | ✗ Side & back sleepers |
| Weight Categories | ✓ 3-Season Traditional Backpackers — 3.55lbs / 1.61kg / 56.85oz | ✓ Avg. Range – 2-3.5lbs / .91kg-1.59kg / 32-56oz | ✓ 3-Season/Top-Only Insulation – 1.06-1.5lbs / .48kg-.68kg / 17-32oz |
A Revolution in the Making!
From the beginning, the Evolution SlumberSac was designed to eliminate the ever present, long-standing pain points experienced when sleeping outdoors
Meet the Evolution SlumberSac™—OWL’s patent-pending wearable sleep system redefining outdoor comfort. Designed for warmth, mobility, and convenience, it lets adventurers move freely and answer Nature’s call without fully exiting their gear. From backyard campouts to backcountry treks, experience a smarter way to sleep outdoors.
It All Began With a Bold Idea.
Midnight trips in the backcountry don’t have to be miserable. Meet the OWL Evolution Slumber Sac: lightweight, versatile, and built to keep you cozy and ready for adventure.
Remember your last camping trip? Wrestling with your sleeping bag during that “midnight call” from Nature? 🥶 OWL’s Evolution SlumberSac™ is a wearable outdoor sleep system designed for warmth, mobility, and hassle-free nights. No more wrestling. No more freezing. Just smarter camping.
Comfort Without Compromise. Adventure Without Limits. Think Inside the Bag! 🦉
Stay Dryer, Longer!
🚿WATER TEST: PASSED🚿 Watch, as we dump water on the Evolution SlumberSac… No soaking, no drama. Our next-gen DWR ripstop nylon repels moisture, keeping you dry even with the footbox open. Engineered for the wild, field-tested, and trail-approved. Mother Nature? Bring it on.
The Birthplace of OWL - Outdoor Wild Life and Evolution SlumberSac: Crested Butte, CO. A great place to sit and ponder ideas about how to make this venture work! #SunsetAtGrantLake
A view, to get ready for the winter brainstorm sesh...
Walking around the mountain office in Fall, clearing your head with fresh mountain air, is a great way to design ideas on how to make better outdoor sleep gear.
Let winter in Crested Butte BEGIN! The PERFECT time to climb into the Evolution SlumberSac.
The backside of "Mount Crumpet" (aka: Crested Butte Mountain) is a great view while working on how to build this idea!
Winter is coming John Snow(MORE!)
January 2025's -25° temps in Crested Butte, CO inspired the need for more heat... Brrrrr!!! Enter the ActiveCore, ThermaCore, and HeatCore Liner. New additions to the product line!
FINALLY! Winter is upon us.
The snow cave proving grounds for the first prototype of the Evolution SlumberSac in Crested Butte
Just regular old day at the OWL - Outdoor Wild Life offices in Crested Butte
A day at OWL in Crested Butte starts early and cold... (predawn views from the office)
The first fan of the OWL - Outdoor Wild Life Evolution SlumberSac. A local Pine Marten known only as "The Fuzzy Felon" stopped by to check out the progress, and see when it will be ready to go to market...
Juniper, after being subjected to the Founder's new "skills" "I don't think I like this 'New You' dude... is this really necessary?" Kevin: "You'll thank me come January, trust me!"
The first view of what the footbox might look like
The Founder Kevin, at OWL - Outdoor Wild Life, learning that this isn't going to be an easy road. But perseverance pays off!
Ever wonder what the first Evolution SlumberSac started off as? A heap of pieces "Frankensteined" together to make the most innovative outdoor sleep gear in almost a century.
The footbox opens (and attaches securely to the shin area for mobility proposes)
The back footbox attaches like the front, can be lowered to get back in the tent, and then zipped back up.
Ready for mobility? The finished V1 Evolution SlumberSac Prototype shown with the front and back of the footbox open and fastened up, and out of the way
Prototype #3 being field tested in the misty, rainy, boggy highlands of Scotland. Prototype #2 got "bagged" ; )
Ready to get up? Just unzip the footbox, put your footwear on, and go!
You can certainly make use of the "facilities" when "Nature Calls"... ; )
"Sleeping bag"? NOT! This is outdoor sleep gear designed to move with you. Whether it's tracking down gear in the campsite, heading out for that midnight pee-break, or just lounging while making coffee by the campfire.
Some of the forms the Evolution SlumberSac can take.
No other sleeping bag in the industry does what the Evolution SlumberSac does, even if it's still in the prototype stage!
Our trusty OWL Assistant, giving the mobility a 'sassy' try.
Walking is VERY easy in the Evolution SlumberSac. Go where you want, without needing to leave the warmth and comfort.
Contact Us
Interested in working together? Fill out some info and we will be in touch shortly. We can’t wait to hear from you!

