Ursack Major Review

Bottom Line

The Ursack Major is one of the lightest and most convenient bear-resistant food storage options available. Unlike bulky canisters, it packs down small and easily fits inside a backpack, making it ideal for ultralight hikers who prioritize minimal pack weight. Its strong fabric and high-tensile strength cord prevent most bears and other critters from escaping with your food, though it doesn’t always keep contents intact. Persistent bears can crush or mash what’s inside or even tear it open on occasion.

Although it’s IGBC-certified for grizzlies, it’s not universally approved in every park or wilderness area.

We’ve used the Ursack in rugged, high-traffic bear zones like Colorado’s Maroon Bells-Snowmass Wilderness, where it offered both convenience and peace of mind. For ultralight backpackers and experienced hikers who prioritize simplicity and weight savings, it’s an excellent choice. For more heavy-duty bear canisters, see our guide to the best bear canisters.

How We Tested

We tested the Ursack for numerous nights during several backpacking trips in the Maroon Bells-Snowmass Wilderness, Indian Peaks, and other areas.

The testing included verifying manufacturer specifications, evaluating its actual packing capacity, and comparing many user reports with our own first-hand experiences in the backcountry.

Weight & Packability

The Ursack is a great way to shed weight while still keeping your food safe from bears. The Ursack Major weighs just 6.3 ounces and measures 12.5 inches by 18 inches when fully packed.

That’s easily two pounds lighter than some of the lightest hard-sided bear canisters on the market. Since it’s a soft, collapsible bag, the Ursack is also much easier to pack than a bear canister. It only takes up as much space as your current food supply.

Ease of Use

The Ursack is simple to use without complicated or frustrating locking systems. The Ursack is designed to be a strong barrier against bears, not a puzzle to trick them. 

Keeping critters out still requires a process to be effective. First, ensure the two cord strands are crossing, then pull the drawstring shut and secure it with a double overhand knot. Bears aren’t the only animals after your food, so it’s important to have a tight enclosure to prevent small rodents from climbing in.

Once tied, you’ll need to secure the Ursack to a tree. A simple overhand knot around the trunk will suffice, but Ursack recommends using a quick-release knot like a slip knot so you can easily untie it after it has been pulled on by a bear all night. If possible, wrap it around a branch a few feet up to make it harder for a bear to get leverage.

Finding the right tree can sometimes be tricky, especially if the trunks are cluttered or branches are out of reach, but in most bear country, a good anchor is usually not far away.

A small but helpful bonus: the reflective cord and tag make it easy to find your bag with a headlamp after dark, so you don’t waste time wandering around the woods looking for your food.

Security

The Ursack’s security mainly depends on two factors: how well you use it and how motivated the local bears are. If you make sure to tie good knots, it’s unlikely that any woodland creature will make off with your entire food bag.

The IGBC has certified the Ursack as effective against grizzlies, though it’s important to note that their tests involve well-fed captive bears, not the hungry, pre-hibernation black bears you might encounter in the wild. Those clever scavengers are notoriously persistent.

In practice, the Ursack usually holds its own against most bears, but it’s not indestructible. There are several reports of persistent bears and other critters gnawing a hole in the UHMWP bag. Even if a bear can’t tear it open, it can still crush, squeeze, and pulverize your food into an unrecognizable mess. You’ll still have your rations in the morning—but maybe not in edible form.

For best results, we highly recommend pairing it with an odor-proof liner like a Smellyproof or Opsack. This combination significantly reduces scent and temptation, keeping your food safer—and hopefully less smushed.

Permit CompatibiLity

The Ursack carries the important IGBC certification for grizzly bear resistance—the key requirement for use in most regulated bear country. However, it doesn’t have a separate certification for black bears, which are often more persistent and dexterous when it comes to food raids.

Even with the IGBC’s stamp of approval, the Ursack isn’t accepted everywhere. Some national parks and wilderness areas still require a traditional hard-sided bear canister, so it’s crucial to double-check local regulations before relying solely on the Ursack.

To make that easier, Ursack prints a QR code inside each bag that links to an updated map showing where its use is approved, restricted, or prohibited. It’s a handy feature that helps prevent surprises when you reach the trailhead.

Capacity

The Ursack comes in several sizes to accommodate different trip lengths and group sizes, including the 10.6-liter Major, 15-liter Major XL, and the large 30-liter Major 2XL, which can hold approximately two weeks’ worth of food for one person. 

The Major is the most popular choice, offering enough capacity for about five days of backpacking meals while keeping bulk and weight low. It’s large enough to fit a SmellyProof Bag filled with 14 Good To-Go meals, or up to around 27 meals if you skip the odor barrier liner. This size is versatile enough for most backpackers on trips a week or shorter.

The larger XL and 2XL versions are ideal for longer trips or small groups. Regardless of size, each Ursack compresses easily when empty and weighs only a small fraction of what a bear canister does.

Should You Buy the Ursack Major?

The Ursack Major is ideal for backpackers and thru-hikers who prioritize low weight, flexibility, and packability over maximum protection. It’s suitable for those traveling through bear country where Ursacks are permitted and who are confident in their food storage techniques—such as tying secure knots, using odor-proof liners, and selecting good tie-off spots.

For lightweight adventurers, it provides a great balance of convenience and peace of mind, avoiding the bulk and awkwardness of a hard canister. 

However, it’s not the best choice for areas that strictly require canisters or for those seeking a completely foolproof barrier against strong bears. The Ursack is slightly larger than a typical bear canister, but if used correctly, it offers a lot of usefulness for a fraction of the weight. For those willing to trade some strength for a lighter, more packable setup, it’s one of the best bear canister alternatives available.

What Other Bear Canisters and Backpacking Food Storage Should You Consider?

Our full guide to food storage options covers everything from security-enhancing accessories to tank-like bears canisters.

Smellyproof Bags Review: Smellyproof Bags (or similar odor barrier) are essential for any non foolproof food storage method. At just half an ounce, they provide added security and peace of mind in bear country. They could be the difference that saves your food and the bear’s life.

Adotec Ultralight Bear Locker: This ultralight bear canister alternative is another soft-sided storage method. Like the Ursack, the Bear Locker benefits from the added security of Smellyproof Bags and easy packability.

Grubcan Carbon 6.6 Review: For hard-sided canisters, the Grubcan Carbon is the closest in weight to the Ursack. It functions like other hard-sided containers but weighs less than two pounds. However, these weight savings for the security of a hard-sided container come at a very high price.