The case for an Ursack and Opsak combo is compelling: they’re lighter and easier to pack than any bear canister on the market, and you don’t have to find the silver lining of carrying a bear can in the old saw “well, at least I have a camp stool at night”.
In addition to protection against bears, the Ursack can also provide protection against mini bears and other habituated or opportunistic creatures!
My well used collection of Ursacks
What is the Ursack + Opsak Food Storage System?
The Ursack is a UHMWP bag strong enough to resist the efforts of bears and critters to get the food inside. It’s approved by the International Grizzly Bear Commission (IGBC).
The Opsak is the companion odor proof food storage bag that goes inside the Ursack. The Opsak features a special film to create the odor proof and waterproof barrier, as well as a double Ziploc-style closure at the top. The 12.25" x 20" Opsak bags pair exceptionally well with the Ursack Major and Ursack Allmitey.
Together they make a formidable defense for keeping humans, bears, and critters safe.
The Ursack ‘Major’ series is bear resistant, but may be susceptible to small tears in the fabric weave from smaller critters.
The Ursack ‘Allmitey’ adds a little weight (and cost) because it features an additional Kevlar lining to go along with the UHMWP. This keeps small critters along with bears. It sports the following specs:
- Allmitey (10.6 liters, 9.3oz)
- Allmitey Grizzly (20 liters, 13.8oz)
- Allmitey Kodiak (30 liters, 15.3oz)
When to Use an Ursack + Opsak Combo?
To start with, DO NOT use an Ursack in a place where the land management authority (National Park Service, National Forest, BLM, State Forest) requires the use of a hard sided food storage container. It is the responsibility of the hiker to know what the food storage rules are for your trip!
Having said that, I use an Ursack most places where a bear canister is not required. In addition to the ease of packing and decrease in weight, many of the barely alpine or high desert camps I find myself at do not have the density or size of trees to do a proper PCT style bear hang.
For National Parks, and a few National Forests, Ursack maintains this approval map on their website. Newer Ursacks have a QR code on their tag directly linking to this map.
To use myself as an example, I live in Portland, Oregon. The closest National Parks to me are:
- Rainier (Ursack Allowed, marked in Green)
- Olympics (Not allowed, marked in Red)
- North Cascades (Allowed, marked in Green)
You may notice some Parks marked in Yellow, such as Redwoods. This means the aluminum accessory liner must be used at these Parks. I have personally done this in Rocky Mountain National Park. The addition of the aluminum liner does decrease the packability, but is still a significant weight savings over any bear canister on the market.
Individual wilderness areas in a National Forest may have their own set of rules. Just this year the Alpine Lakes Wilderness in Washington began requiring either Ursacks or bear cans.
If you consider that the Washington portion of the PCT passes through this wilderness area not long before entering North Cascades National Park, an Ursack is a must-have for any PCT hiker who sent their bear can home as soon as they finished the Sierra!
It's not hard to see why forest managers are requiring increased levels of protection for food in highly trafficked areas. Here I am earlier this summer just off the PCT in the Alpine Lakes Wilderness, showing an overly friendly deer that I am armed with an Ursack and no easy target!
How to Use an Ursack + Opsak Combo?
The picture above shows a near perfect scenario for a hang. The Ursacks are tied a little above shoulder height, so as to prevent extra leverage for a bear; and equally important is that the hang is well out of our campsite but DIRECTLY in our line of sight. This is not always possible but is the ideal. If a bear messes with the Ursacks at night, in all likelihood we will hear them and I’ll be able to see what's going on quickly with my headlamp. At this point I’d make some noise and shoo the bear away.
It’s worth noting that doing a full bear hang with your Ursack is always an option, and may allow you to comply with land management regulations in places that limit the use of an Ursack.
How and Where to Hang an Ursack?
A video is worth a thousand words, right?!? But here are the bullet points to remember in the field:
- Cross cables over the opening. Make sure the food inside is NOT visible.
- Tie a double overhand knot. Cinch down tight.
- Tie Ursack to a tree. Ideally use a slip knot. Place it about 5 to 6 feet high. Tie to the trunk of a tree, just above a large branch.
Ursack’s website has further instructions here. Reading them you can see the reasons for my hang being ‘near perfect’. Ursack does not recommend hanging multiple Ursacks in the same place, and we didn’t have a branch on our tree. The established site we were in was somewhat denuded by campers stripping branches for firewood, so we did the best we could.
What Size Ursack is Right for Me?
If you are just buying one Ursack (like everything in my gear closet, I have multiple) it seems to me the Allmitey would be the best fit for most hikers. It offers about the same capacity as a BV 500 and the best protection against both bears and small critters. Most people will say this is about 5-7 days of food, but obviously this is dependent on the hiker. If you really aren’t sure what volume will work for you, find a silnylon stuff sack or a couple gallon ziplock bags to measure the volume of food you typically consume per day.
Food storage safety is the responsibility of every hiker, which means knowing the rules of each area you are traveling through and complying with the regulations in place. The Ursack + Opsak system often gives you a chance to do just that while cutting several pounds of weight and considerable volume out of your pack!