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Built Worldwide

Our largest expedition backpack for your biggest adventures.

The T-100 is our most gargantuan, expedition backpack. While its legacy lines are identifiable, it incorporates our latest fabrications and design updates. The core features and top-loading design stay true to its Terraplane little brother, yet you’ll find significant advancements in construction and materials. The T-100 represents both our heritage – in a plus size – as well as our latest, Load Carriage™ vision.

  • Mountain Frame with adjustable yoke
  • Built with 500D CORDURA® for long-haul durability
  • Top-loading design for easy packing
  • Two vertical “torpedo” pockets for external access
  • Speedzip™ compartment for easy access to sleeping bag
  • Side zip for easy access without unpacking
  • Water bottle pockets keep hydration handy
  • Hydration reservoir compatible
  • Volume: 6100 cu-in (100 L)
  • Weight: 7.43 lb (3.22 kg)
  • Frame System: Mountain Frame
  • Country Of Manufacture: Imported
  • Intended Use: Backpacking, Expeditions, Extended Backpacking

Frequenty Asked Questions

We're moving to a kitted system so that we can design and build packs and frames that are optimized for integration based on the function of the product. There are some cool new things in the works. In the meantime, we may be able to accommodate pack only orders based on available inventory - contact MR Customer Service or call 406-585-1428

As much as we would like to be able to offer our military/LE/ firefighter customers a discount on our packs, we have government contracts in these markets that prevent us from doing so.

The only repair that we can offer on Dana Design products is a replacement back foam pad on packs with the ArcFlex body panel design. We can ship the foam to you and you can easily install it yourself without having to send the pack in to be repaired. Replacement back foam pads are $15.00 plus shipping. For any other Dana Design pack repairs, please contact Marmot or try the following reputable gear repair companies:

Marmot Warranty:

(888) 311-2900

Mon - Fri : 7:30am - 5pm (PST)

Boulder Mountain Repair:

2200 Central Ave. Suite F

Boulder, CO80301

(303) 499-3634

Rainy Pass Repair:

4415 Stone Way N.

Seattle, WA98103

(206) 523-8135


We are not set up to perform custom work on individual orders and no, we cannot build a pack for you in a custom color. If your concern is in regards to sizing please give us a call at 406-585-1428.

Also, please know that modifying your Mystery Ranch pack may void the lifetime warranty, so please think first before you start ripping straps off and cutting holes in your pack to make it more aerodynamic for winged flight.

First, start by washing your pack with hot water in the shower. Use a mild detergent like Dawn to get minor dirt and grime out of your pack. Dry the pack out of direct sunlight. DO NOT USE HARSH CHEMICALS TO CLEAN YOUR PACK. If you need to get odors/blood out of your hunting pack, please use Atsko Sport-Wash Laundry Detergent

We always recommend that you size down for the waist belt. If you fall in-between sizes on the yoke, we recommend that you size up.

Mystery Ranch accepts returns for a refund within 60 days of the original purchase date. Items must be returned in brand new, unused condition, and shipping charges are non-refundable. Please give us a call at 406-585-1428, and we can get you set up with a Return Authorization (RA#).

If you are in need of a different size yoke or waist belt, please give us a call at 406-585-1428.

Why did you add a production facility in the Philippines?

MYSTERY RANCH added these facilities because of the increased demand for our product. We needed the additional facilities to build for customers who don't require (Berry Compliant) US production and / or don't want to pay a premium price for products built in the U.S.A. With these additional offshore facilities, we are able to focus our domestic facilities on the Berry Compliant orders.

How do I know if the pack I want is made in the US, PH, or VN?

It will be noted on the product page on our website and you are always welcome to call us and ask if you don't see the "US" or "world" icons that denote production location.

Is the quality of the packs the same?

Yes, absolutely! We carefully select the highest quality materials and ensure that all production facilities adopt our quality standards and techniques to deliver products consistent with the MYSTERY RANCH legacy. Our distributors who have received product from the US, PH, or VN are unable to tell the difference without looking at the label.

How do you ensure consistent quality?

Our factory resources use the protocol defined by our team in our production packages in order to deliver consistent quality gear. Upon introduction of new products, our product engineers visit our factory resources to work with them to develop new styles. As the product goes to production, our QA and QC teams will then visit our US, PH, and VN factories to ensure the finished goods meet our MYSTERY RANCH standards.

For more information please contact MR Customer Service or call 406-585-1428

I have the Arcflex Astralplane (a mouthful, but google it, the reviews are uniform in that it's the best big pack ever made), which I think is the same as the T-100 above. I got mine in 1990 or something. It has been on every continent save Antarctica, up the AT, the PCT, winter camping, summer camping, etc. I lived out of it in Argentina for a year, and Costa Rica for 2 years, plus 3 other countries where I spent a number of months. Put it this way, I was a sophomore in college when I got it, I'm now 45 years old, and the thing might as well be brand-new, other than being faded and dirty. Nothing's ripped, nothing's broken. It's ridiculous how well built and designed it is; and it looks like other than a few tweaks it's the same pack all these decades later. Unreal! One thing to note is that this thing is NOT a lightweight pack, but that's because you can load it up with up to a hundred pounds and it won't complain at all, and it'll feel like half that on your body. The suspension system is so good. I tend to do lighter weights now, and don't travel as much with it anymore unless I'm on a dedicated trekking trip (hello, 4-wheel spinner bags!), but I can't imagine ever needing a new expedition pack, other than fantasizing about somehow attaching an ArcTeryx pivoting hip belt onto this. (Blasphemy?) In any case, if you're on this page and wondering if it's worth it, take it from me: BUY IT
Mystery Ranch T-100
Pro’s and Con’s
First, let me say that this is one great comfortable well built pack. The way this thing rides on my back is like no other. (I own a Kelty Red Cloud, Osprey Atmos and a couple smaller packs) The craftsmanship of this pack is way above the others and carry’s loads of 40 – 60 lbs very easily. It will carry more but that’s all I have put in it so far.
Now, for a few minor con’s but important ones to me anyway. This pack does not have the little clip attachment inside the lid for attaching a small wallet and or keys. To me this is a very necessary little piece of the equipment. I hate carrying keys and wallet in my pockets. I love and have come to depend on this little piece in my other packs for always knowing where my keys, ID and some cash are. Now with the T-100 I fear having to fish around for where I put these items or worse, them falling out unknowingly on the trail somewhere when I opened the lid for a compass, map, wipe or other little items I tend to keep in the lid close at hand. Next is the hydration issue. I found the two slots on either side at the top to run the hose out but there is no pocket on the inside of the bag to insert a hydration bag next to the frame side. This pack is so massive; the hydration bag gets mashed in with all the other gear and if hiking long distances before unloading the pack, make it difficult to remove the hydration bladder to refill. Plus, it slides to the very bottom of the pack and puts a strain on the hose. The Hydration bag is supposed to go in one of the lid compartments and feed the hose from there. I don’t like this as it takes up lid space I use for other items. Last is the lack of those small pockets in the belt that I use to keep a small camera, some bug spray, sunscreen or sometimes a few meds that make it super easy to get to on the trail while walking. These may seem minor and I guess they are but Dana and crew could have added these (at least the 1st 2) with little to no extra cost and weight to the pack.
I really love this pack and can see it lasting longer than I can continue hiking and camping. Just wish the few little details mentioned above would have been added. Especially the little clip for the wallet and keys… Rick