Mayhem EVO 45L Backpack

Color
Loden

A robust and multifunctional 45 liter pack built for those heading into the backcountry. Designed with unique internal and external modular organization options to carry essential gear for your next wilderness adventure. This pro-level backpack helps keep you prepared for any challenge in the field.

Your extended outdoor mission just got a whole lot more EVOlved.

With design input from variousColorado-based Search & Rescue teams, the Mayhem EVO 45 liter backpack is designed to meet the demands of outdoor working professionals, search and rescue teams (SAR), hunters, rangers, trail crews, arborists, survivalists and any outdoorsman who needs uncompromising durability, gear carrying capacity, and best-in-class organization.

This Swiss Army Knife of packs, features custom positioned, girth hitched compression straps and a reversible front beaver tail panel (Hi-Vis Blaze Orange) allowing you to easily secure and organize your gear while staying visible in challenging conditions. Bottom panel loops allow for external A-Frame ski carry and the V-Cinch top compression webbing allows for rope management or even securing a small-to-mid size chainsaw body in the field. The wide clamshell-style main compartment offers easy zippered access while maximum visibility is the rule with its blaze orange lined interior. Internal organization features include zippered mesh pockets, a PALS webbing panel (the waistbelt accessory pocket can be relocated here), vertical daisy chains for climbing gear organization, vertical slash pockets, hook & loop panel for accessory attachments, and an internal hydration bladder sleeve carries up to 3L (not included). Modular compression straps allow for customizing your load carrying style and the shoulder straps integrate with our new Timber EVO (SM / MD) or our ZERK 3L Loki Lumbar convertible waistpack for additional EDC chest carry options. Use the waistbelt PALS webbing to carry our extra, zippered accessory pouch, The Roo or go even more robust and slap a Timber EVO (SM / MD) on the padded waistbelt with its provided MOLLE system...bomber!

FEATURES

  • Hybrid panel / top loader system with wide zippered opening interior access
  • Front panel expansion sleeve with attachment loops and accessory zippered pocket (Reversible for Hi-Vis, Blaze Orange Safety Panel)
  • Lower section of front panel allows for pass-thru for snowboard carry, blade-down chainsaw carry, hand tool carry (shovel, McLeod, Rogue, axes, etc.) and is removable when necessary
  • Dual side bottle pockets with field serviceable bungees
  • Modular compression straps (girth hitched) for custom carry options and positioning
  • Front panel zippered pocket with expansion gusset
  • Dual sternum straps for increased load management during physical activity
  • Load lifters on shoulder straps for additional custom fit and weight management
  • Rope and A-Frame ski carry for backcountry pursuits
  • Removeable high density foam framesheet with hoop frame load dispersion
  • Forward pull waistbelt with side PALS webbing & modular MOLLE-style accessory pouch
  • Dual zippered, color-coded compartments on top panel
  • Front panel hook & loop patch panel for agency badges, morale patches, accessory attachment, etc.
  • Dual side panel bottle pockets with over-under strap pass thru
  • Ice axe & mixed tool lower panel storage sleeves (Hypalon reinforced)
  • Exterior body fabric backpanel helps shed ice, snow, mud and dirt
  • Shoulder straps allow for accessory chest carry of the Timber EVO SM or MD (Available Spring 2026) or our ZERK 3L Loki Lumbar (Available Spring 2026)
  • Bottom panel compression straps for additional load carry
  • Hi-vis, Blaze Orange interior for maximum visibility
  • MATERIALS

    • 420d Nylon Ripstop Dobby w/ DWR*
    • 150d High Density Poly Liner*
    • YKK® Zippers
    • EVA Foam
    • *There are no intentionally added PFAS in this item

    CALIFORNIA WARNING: Cancer and Reproductive Harm | www.P65Warnings.ca.gov

    DIMENSIONS

    • 26" x 11.5" x 8.25" (H x W x D)

    VOLUME

    • 2685 in3 / 44 L

    CAPACITY

    • Waistbelt Size Range: 29"-48"
    • Torso Size Range: 16"-20"
    • Weight Load: Suggested up to 55 lbs

    WEIGHT

    • 4 lb 4 oz

Customer Reviews

Based on 4 reviews
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D
DevilDoc Hudson
Great Search & Rescue Pack: 4.5/5 Stars

First of all, I really like this pack and I think it's very well designed for a single overnight mission. I have a Taller torso so I needed to go with the EVO 45 versus the EVO 30 L model. It holds quite a bit of gear. I like the top lid having two sequestered pockets, each with its own zipper: one on the left and one on the right that lay on top of each other. I also like the addition of the bilateral internal Daisy chains. I use tiny little carabiners to suspend gear like 550 cord etc. and the craftsmanship is spot on. The oversize zipper tabs are nice and easier to pull them long thin ones. I liked the blaze orange contrast to make things pop quite a bit more. There are a lot of great things about this product, but I need to focus on the areas where it can be improved. (HEY MountainSmith, I have more than 35 years in the backcountry and am more than happy to talk to the designers or even test gear for you!)

There are a few detractors which need to be addressed:
1. While this is rated for up to 55 pounds, a bit heavier load than the EVO 30L, the way spelt is identical to the EVO 30L. Hence, I question whether the waist belt is beefy enough to hold up to that extra weight over an extended period of time. I've only had it a few weeks using the EVO 45L now, but the padding in the waist belt is not a very firm pad and I feel it might break down sooner than it should. To remedy this, I think a dual density foam would be ideal in this case.
2. First: need more Molly webbing on the back of the pack to attach other pouches if needed. Search and Rescue (especially us in mountain rescue) is very niche and requires different configurations which are not afforded well by the current design. Second: The fixed runs of Molle straps on the waist belt don't mesh fully with the available webbing due to the snapping retention tabs being too short to encircle all of the Molle webbing on both surfaces. While the fixed funs of Molle webbing on the waist belt and the accessory pouches line up well, due to the short length of the retention tabs, with the snaps you are only able to use a total of three of the runs of the fixed webbing: Either two runs of the fixed webbing on the waist belt and one on an accessory pouch or two runs of the fixed webbing on the accessory pouch and one on the waist. You can't fully interlace all four of the runs of the fixed webbing, which is the purpose. Solution: Simply make the retention tabs longer.
3. I bought the medium accessory pouch to create a chest rig like the pictures in your product description, but there are no instructions on how to set it up. On the EVO 30L, a chest rig setup can easily be attached through the polymer buckle on the shoulder straps. However, this cannot be done on the Evo 45L because the existing strap doubles back through the buckle narrowing the space that you could attach the chest rig through the polymer buckle. The shoulder straps MUST have separate attachment points in this fashion that can move vertically along these shoulder straps.
4. The shoulder strap configuration needs to have the accessory pockets set lower on the straps so that they're not right up against your cheek when you bend your neck down. The strap padding should be long enough to move the accessory pockets lower on the straps by at least 4 more inches. The other option is to make the strapping system separate such as a small medium large torso strapping system. (However, you still need to set the accessory pouches lower because it will still hit the same place proportionally on a person who has a short, average or tall torso.)
5. You need to make a product video which shows how to utilize each of the different areas of the backpack. I DO NOT intend rudeness when I say this: Take a look at how Mystery Ranch does their product videos. Have examples of how how to reverse the stash pocket so that the blaze side is out; show a picture of the ice tools inset into the Hypalon sleeves; in the video show how to attach the optional chest rig set up that you show in the pictures; demonstrate some internal configurations utilizing the Molle strapping inside the stash pocket or the purpose of the Molly webbing on the inside of the backpack lid; demonstrate a radio setup utilizing the left shoulder strap radio pocket with the retention Velcro in place over the antenna, etc., etc.

OVERALL: I love this pack!

J
Josh Hopkins, R15 EPCSAR
THE go to for high altitude SAR

This pack is the most versatile pack on the market. Pockets and storage everywhere but nothing gets lost due to the different colored zippers and pulls.
The blaze orange interior makes it impossible to loose even the smallest item. The strap pockets can hold a marathon bottle, GPS AND radio. The external tiedowns hold trekking polls, snow shoes, and mountain axe perfectly.

M
MarkB
Great all around pack

Great all around pack. Love tthe interior accsss and organizational possibilities

J
John Williams Routt County SAR
Backcountry SAR - This pack is my new go-to for the tough missions.

I'm sold. Lots of pockets, designed for on-the-move access to essentials, and when you need to get into the main storage area boom, open the clamshell and your into all of it. So important when you're operating under extreme conditions and every moment is critical.