Ursack at a glance
- Fabric
- Cut-resistant UHMWPE weave
- Weight
- Roughly 8 oz against 2 to 3 lb
- Accepted
- Only where explicitly listed
What an Ursack is
An Ursack is a sack of high-strength cut-resistant fabric, in the current models a UHMWPE weave, with a cord closure. Tied properly to a tree trunk, a bear can maul it without tearing through, so the food stays contained even though the bag deforms.
Why people carry one instead of a canister
The appeal against a canister is obvious: far lighter, packs flat when empty, and shapes itself to whatever space is left in your pack instead of dictating the shape of everything else. On a long trip that's a real difference in both weight and volume.
The two caveats
Two caveats matter. First, contents get crushed even when the bag holds, so anything you'd rather not eat as powder needs protecting, and an odour-proof liner is usually recommended alongside it. Second, and more important: acceptance varies. Some units accept certain Ursack models, others require a hard-sided container and explicitly don't allow soft bags. It's the same rule as everywhere else in food storage, which is that the land manager's current list is the only authority worth trusting.
What this means when you're choosing
- Whether the specific unit you're visiting accepts the model you own
- The correct tie-off, since the bag only works if it's secured properly
- An odour-proof liner, which most guidance suggests using with it
The common mistake
Assuming it is accepted where canisters are required
It is a different product class and many units that mandate a canister do not list it. Where it is allowed, tie it correctly to a live trunk with the knot the maker specifies; tied wrong, it comes away with the bear.
Common questions
Is an Ursack allowed instead of a bear canister?
Sometimes, and it depends entirely on where you are. Some areas accept certain models and others require a hard-sided container. Check the specific park or forest's current food storage rules before you rely on one.
Do I still need to hang an Ursack?
No, it's designed to be tied off to a tree trunk at ground level rather than hung. Follow the manufacturer's knot instructions, because a poorly secured bag can be dragged away whole.
Where this is defined
- Certified bear-resistant products list, Interagency Grizzly Bear Committee