Hanging a bear bag is not easy, but it is essential for keeping safe. In almost all parks and places where bears are present, law requires that food is kept away from bears. Regardless of the legal aspect, backpackers have a moral obligation to keep their food away from bears. Bears which get food are more likely to become a problem for humans and very often these bears are killed. Even when bears are not present, there are plenty of animals who would happily steal foo – rats, squirrels, raccoons, etc…
Bear canisters keep food safe from animals and can make good seats, however, they are heavy and bulky. Most backpackers prefer to make use of bags to hang food out of reach. Some areas require bear canisters by law (check before leaving).
Bears and other animals have a fantastic sense of smell compared to us humans. Putting food and other oder giving substances in an oder proof bag reduces the oder. This in turn reduces the distance and number of animals which will smell the food.
Even foil sealed dehydrated food will give off a scent. Simply touching the bag on the outside will leave a small tell-tale oder. Putting food in an oder proof bag, will however, reduce the number of animals who will detect the oder. LokSak bags are designed to keep this odor down.
A great (but pricy) alternative to bear canisters are Ursack bags, see review here. These are relatively light weight and whilst larger than a compression bag, they are much less bulky. On the TRT through hike we put all our food in LokSak bags and then used a Ursak and lifted it 10+ feet away from the ground every night.
Ideally, your bear bag should be hung downwind from your sleeping area 100+ ft away (150+ ft is better) and also away from the cooking area. This all sounds great, but in the real world, finding a camp site and an appropriate tree with these specifications is often difficult (plus wind directions change). Use common sense, there are animals who are looking for an easy meal and are attracted to anything that could be just that ticket.
Do not cook or hang your food over your tent, do not cook/eat close to your tent, and double check for any snacks which may be left in backpack side pockets/clothes pockets. Do consider all smelly things as food such as toothpaste, suncream, and the like. Put all these in the bear bag. Also try not to spill food on any clothing you will take/wear to bed, if you do, clean the worst off that night and put it in the bear bag and do a more thorough clean in the morning.
Use a 50ft length of para-cord and a lightweight stuff-sack or Ursak. A small (fist sized) sack filled with rocks is also useful for throwing the cord over a suitable branch.
Find a branch which is about 12-15ft high, strong enough to take the weight and fairly free of growth (to avoid the cord from being entangled) but far enough out from the tree that it cannot be reached from the trunk.
To keep weight down a narrow cord seems to be the best choice. The problem with narrow cord is that it is more likely to snag in the structure of the bark of the tree and is more likely to cut into the bark and create sufficient friction to stay put which means no more food. Although thicker cord is heavier, I’d recommend it to avoid snagging.
Toss the cord over and attach the end to your food bag with a carabiner or figure eight knot. Pass the cord through the carabiner and haul the bag up. Holding the cord so the bag stays all the way up, reach as high as you can and use a clove hitch to secure a handy stick. Let the bag down slowly until the stick reaches the carabiner and stops the bag falling further.
This scheme works well, there is no cord that can be cut by a bear claw to get the bag down – a bear would need to reach beyond the bag. The down side is that holding the weight of the bag whilst tying the knot seems to require three hands. Plus, the bag will drop down and may not be high enough.
For example, if the branch is 14ft high and the clove hitch is tied at 8ft, the bag will drop half the distance between the two – 3ft. Now the bag is 11ft off the ground which is not a sufficient hight.
Additionally, since the cord is wrapped the entire way around the branch and back to a central point (the carabiner) there can be, depending on the branch and cord, a lot of friction between the cord and branch. On one occasion, come morning time, pulling on the cord had no effect. No way to reach the clove hitch, no way to reach the food. Eventually this friction was overcome, however, had the cord broken we would have lost all our food. Enough of a scare to dissuade for this method.
Same as above but instead of reaching and tying a clove hitch around a stick, tie the end to a nearby tree. This allows for better adjustment of the final height, however, now the end which is securing the bag is much lower. If this cord is broken, the bag will fall to the ground. Bears are smart, (ever tried catching a salmon mid flight)? Method 2 is fine outside bear country but not recommended in it. Use of an Ursak bag makes this more acceptable.
Some backcountry campsites have bear poles.