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Location Where Tests Were Conducted:
We have used two Ursack bear-resistant bags on our section hikes of the Appalachian Trail in Georgia, North Carolina, and Tennessee in 2004. The first hike took place in March in Tennessee for four days, the second from Fontana Dam to Deep Gap in June. Elevations ranged from 1800 feet (549 m) at Fontana Dam to over 5800 feet (1768 m) at Round Bald. Nighttime temperatures were in the mid-twenties F (-5 C) on the March trip, and around 50 F (10 C) in June. We have also used the bags on several overnight and long-weekend hikes in the Mt. Rogers area in southwest Virginia this summer.
On last year’s section hike in Georgia, we had numerous problems with mice and other small rodents getting into our food bags (regular silnylon stuff sacks), even when we hung them from the installed bear cables. Every morning we found new evidence that mice and other small critters were able to get inside our bags: little holes in the food bags, mouse droppings in the gorp, hot chocolate mix all over the inside of the bag. This year, we used the Ursacks to store our food and other items that might attract animals, hanging them from the bear cables where available, or inside the shelter, or tied to a tree near our campsite. The result? No evidence of mice or other small critters inside the Ursacks.
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| Product Information:
Description:
 The Ursack is a large stuffsack made of aramid fibers, the same fabric used in bulletproof vests. Flat, the Ursack is 16 inches (40.6 cm) tall by 12 inches (30.5 cm) wide, and has a Spectra fiber cord with a cordlock to secure the opening. Filled and closed, the Ursack is approximately 7 inches (18 cm) in diameter, and 14 inches (35.5 cm) tall. The green-colored fabric is heavy enough that it feels like stiff leather or canvas. The bag is made from two pieces of this fabric, with a huge 1.5-inch (3.8 cm) seam allowance (see picture at right) and four rows of stitches at each seam. The rows of stitching are spaced unevenly in places, and detract from the otherwise well-made appearance of the product.
The Ursack has an unusual closure system: the cord pulls closed at the top in a metal grommet like any other stuff sack, then runs back through a second grommet in the opposite side of the bag. Pulling the cord pulls the two grommets together and completely closes the top of the bag. This prevents small animals like mice from entering the bag. (See photo.) The ends of the cord are finished with what appears to be heat-shrink tubing, which slipped off the first time I handled it.
The Ursack comes from the manufacturer inside a large plastic zipper-lock bag. This bag is meant to be used as a liner inside the Ursack; the manufacturer claims that the bag is 10,000 times more odor-resistant than a standard Zip-Loc bag. The Ursack also comes with a comic-book style owner’s manual that has some good information about bear behavior.
The manufacturer sells the Ursack for use as a bear resistant bag. I haven’t had the opportunity to test this feature. I purchased the bags to keep out the more common critters in the southeastern U.S., especially the shelter mice that are endemic to the Appalachian Trail. Please note that as of this writing the Ursack has not been approved for use in several areas in the Sierra Nevada mountains (see the Yosemite web site for more details). This means that the Ursack cannot be used in parts of Yosemite and Kings Canyon.
Using the Ursack:
When I first opened the Ursacks, they looked big – almost too big. Then I started filling them with food for our first trip, and they suddenly started to shrink before my eyes. But with a little work, I was able to fit three and a half days of food for three people into two Ursacks. That’s a total of nine breakfasts, twelve lunches, nine dinners, and three days worth of gorp, dried fruit, drink mixes, and snacks for three people. I also fit three small bowls and a 110 g (4 oz) butane canister. We carried our first day’s lunch and snacks in our pack pockets rather than in the Ursack, though I think we could have fit them inside the bags. The total weight was about nine pounds (4 kg) per bag, including the Ursack itself. That translates to a little less than 1.5 pounds (0.7 kg) of food per person per day for a mild winter trip.
The odor-barrier liner fits exactly inside the Ursack, leaving about 4 inches (10 cm) of usable space on top of the liner once it’s full and closed. I found this space useful for small extras like the bowls, extra butane canister, and other ‘smellables’ like toothpaste, which we hung with our food at night. (As we consumed our food, I was able to put all the smellable items inside the odor barrier, which is preferable. I would like to see a larger odor-barrier bag that uses all the space available inside the Ursack.)
I had mixed results when I loaded the full Ursacks into our lightweight packs (a Gregory Z Pack, size small, and an Osprey Aether 60, size large). The bad news: it is possible to load an Ursack so that it won’t fit into these packs lying on its side. The good news: unlike a hard-sided bear canister, the Ursack can be made smaller by taking out some food, or rearranging the food inside. With a little fiddling, I was able to get the Ursacks in our packs. In my wife’s Z Pack, she found that the best place for the Ursack was lying sideways in the very bottom of the pack, with her sleeping bag, pad, and clothing bag on top. I have a larger sleeping bag, which I put at the bottom of my Osprey pack, and the Ursack fit nicely on top of it, also lying on its side. I also tested a fully-loaded Ursack in our larger packs, a Gregory Shasta (size large) and a Lowe Sirocco, and it fit easily into both packs.
When I was ready to go to bed at night, I followed the manufacturer’s directions for securing the Ursack TKO. First, I closed the top of the bag by pulling the cord tight, then through the second grommet to seal the top. Then I pushed the cord lock down tight, and tied an overhand knot over the cord lock to secure it. At this point, the directions say to tie the Ursack to a tree using a figure-8 knot. There is no need to hang it from a high branch, or to counterbalance it with another bag. The manufacturer claims that the Spectra cord is strong enough that bears and other animals can’t break it or chew through it, though I didn't see any animals trying to do so. I did try cutting the end of the cord with scissors, and it is resistant to cutting.
On our March trip, I laid the Ursacks on the floor inside the shelter and tied the cord around a board in the wall. There was no evidence of rodent activity at night, and the bags were fine in the morning.
On the June section hike, we stayed in shelters every night but one, and we saw rodent activity in most of them. Depending on what was available in each shelter, I hung our Ursacks on the installed bear cables, on the ‘cord and stick’ hangers commonly found dangling from the shelter ceilings, or on nails in the shelter walls. On our several summer weekend hikes, I simply tied the Ursacks to a nearby tree, either at ground level or from a low-hanging branch.
Does it work?:
The problem with answering this question is that I have wealth of negative evidence: no little holes chewed in our food bags, no mouse droppings inside the stuff sacks, no chewed-up toilet paper or pack towels. Since I wasn’t able (or willing) to conduct a controlled test, leaving a second food bag in a regular stuff sack to see what happened, I can’t say with complete certainty that the Ursacks made any difference at all. That’s the left-brained scientist in me talking.
However, all that negative evidence was enough to convince me of the value of the Ursacks. I sleep a lot better at night knowing that I won’t have little critters swarming through my precious food like bargain hunters at an after-Christmas sale.
One important note: I didn’t buy these bags to defeat bears, and I was lucky enough not to test their bear-resistant properties. The manufacturer sells them as bear-resistant bags, and they have a great video on their web site showing a bear trying (unsuccessfully) to rip open an Ursack, but I have no personal experience with this. I do understand that there have been documented failures in which the Ursack was breached by a bear, and the Ursack is not approved in several bear-intensive areas of California.
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