Bear-resistant food storage containers, also called bear canisters or bear cans, are usually hard-sided containers used by
backpackers to protect their food from theft by
bear
Bears are carnivoran mammals of the family (biology), family Ursidae (). They are classified as caniforms, or doglike carnivorans. Although only eight species of bears are extant, they are widespread, appearing in a wide variety of habitats ...
s. Bear canisters are seeing increased popularity in areas where bears have become
habituated to human presence, and are required
in some places, such as
Yosemite National Park
Yosemite National Park ( ) is a List of national parks of the United States, national park of the United States in California. It is bordered on the southeast by Sierra National Forest and on the northwest by Stanislaus National Forest. The p ...
in the
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...
.
Construction

A bear canister
typically weighs between 2–4 lb (1–2 kg), and has a storage capacity of 400–900 in
3 (6–15 liters). The actual capacity in number of days of
hiking
A hike is a long, vigorous walk, usually on trails or footpaths in the countryside. Walking for pleasure developed in Europe during the eighteenth century. Long hikes as part of a religious pilgrimage have existed for a much longer time.
"Hi ...
food stored varies with the appetite of the
hiker
A hike is a long, vigorous walking, walk, usually on trails or footpaths in the countryside. Walking for pleasure developed in Europe during the eighteenth century. Long hikes as part of a religious pilgrimage have existed for a much longer tim ...
, the selection of food, and the skill in which it is packed, but a 700 in
3 canister likely holds up to a week's worth of food for the average hiker.
Hard-sided bear cans employ such materials as
polycarbonate
Polycarbonates (PC) are a group of thermoplastic polymers containing carbonate ester, carbonate groups in their chemical structures. Polycarbonates used in engineering are strong, toughness, tough materials, and some grades are optically transp ...
,
ABS plastic,
carbon fiber
Carbon fiber-reinforced polymers (American English), carbon-fibre-reinforced polymers ( Commonwealth English), carbon-fiber-reinforced plastics, carbon-fiber reinforced-thermoplastic (CFRP, CRP, CFRTP), also known as carbon fiber, carbon comp ...
, and
aluminum
Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has ...
in their construction. An effective canister must resist both the tremendous strength and high
intelligence
Intelligence has been defined in many ways: the capacity for abstraction, logic, understanding, self-awareness, learning, emotional knowledge, reasoning, planning, creativity, critical thinking, and problem-solving. It can be described as t ...
of an attacking animal. Most containers are too large for a bear to simply pick up and carry away.
A captive bear attempting to open a bear canister
The
lid
A lid or cover is part of a container, and serves as the closure (container), closure or Seal (mechanical), seal, usually one that completely closes the object. Lids can be placed on small containers such as Tub (container), tubs as well as large ...
of a canister is usually recessed in order to prevent it being pried off. Some manufacturers, such as Garcia require a tool such as a coin to open the canister whereas other manufacturers' products, such as the BearVault, use locking nubs that allow the user to twist the lid off without tools.
At least one model of soft-sided "bear bag" is made from Spectra (
UHMWPE
Ultra-high-molecular-weight polyethylene (UHMWPE, UHMW) is a subset of the thermoplastic polyethylene. Also known as high-modulus polyethylene (HMPE), it has extremely long chains, with a molecular mass typically between 2 and 6 million amu. The l ...
) fabric. While a soft-sided container may prevent a bear from
eating
Eating (also known as consuming) is the ingestion of food. In biology, this is typically done to provide a heterotrophic organism with energy and nutrients and to allow for growth. Animals and other heterotrophs must eat in order to survive – ...
its contents, the food inside is likely to be reduced to
purée
A purée (or mash) is cooked food, usually vegetables, fruits or legumes, that has been ground, pressed, blended or sieved to the consistency of a creamy paste or liquid. Purées of specific foods are often known by specific names, e.g., appl ...
in the attempt and leak through the Spectra fabric; thus feeding the bear. A newer model comes with an aluminum stiffener that protects the contents more effectively than the bag alone.
Regulations and testing
Several
national park
A national park is a nature park designated for conservation (ethic), conservation purposes because of unparalleled national natural, historic, or cultural significance. It is an area of natural, semi-natural, or developed land that is protecte ...
s and national forests require
backcountry
In geography, a backcountry, back country or backwater is a geographical area that is remote, undeveloped, isolated, or difficult to access. These areas are typically rural or mountainous and sparsely populated.
Terminology Backcountry ...
visitors to carry approved food storage containers. Backpackers who ignore this policy may face fines, property impounded, or eviction from the wilderness.
Rangers may stop hikers and require them to produce their containers for inspection.
The
Sierra Interagency Black Bear Group (SIBBG) and the
Interagency Grizzly Bear Committee (IGBC) regulate the approval of food storage containers in parts of the western United States. Containers effective against the
American black bear
The American black bear (''Ursus americanus''), or simply black bear, is a species of medium-sized bear which is Endemism, endemic to North America. It is the continent's smallest and most widely distributed bear species. It is an omnivore, with ...
s in the
Sierra Nevada
The Sierra Nevada ( ) is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primari ...
may not be effective against the
grizzly bear
The grizzly bear (''Ursus arctos horribilis''), also known as the North American brown bear or simply grizzly, is a population or subspecies of the brown bear inhabiting North America.
In addition to the mainland grizzly (''Ursus arctos horr ...
s found elsewhere. SIBBG conducts visual inspection and various structural tests, then containers are filled with food and left in the cages of captive black bears in a
zoo
A zoo (short for zoological garden; also called an animal park or menagerie) is a facility where animals are kept within enclosures for public exhibition and often bred for conservation purposes.
The term ''zoological garden'' refers to zoology, ...
in
California
California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...
. If the canister survives the zoo test, it is then ''conditionally'' approved. Full approval is only given after three months' successful field tests by users.
The (IGBC) first conducts a visual inspection to identify products that may be harmful to humans or the captive test bears. Next, food such as peanut butter, fish, or other attractant will be placed inside the container. This container will then be put in the grizzly bear enclosure at The Grizzly & Wolf Discovery Center in West Yellowstone Montana. To pass the IGBC certification, a bear must have a total of one hour of direct contact with the product, not counting licking. The product must remain functional and have no penetrations larger than 1/4 inch.
It is recommended that canisters be left on the ground, at least 100 feet/30 metres from the campsite. Suspending the canister can allow the bear to smash it to the ground or use the suspension gear to carry it away. Most canisters are designed to resist clawing and biting from bears rather than loaded drops from trees or cliffs. To prevent a bear from rolling it away, a hiker can leave the container in a bush, a shallow depression, or wedged between rocks or logs. Placing the canister near water could allow the container to float away. Reflective tape and labelling the container helps in recovery.
Bear bagging
An alternative is ''bear bagging, also called bear hanging or bear hangs'', wherein items attractive to a bear such as
food
Food is any substance consumed by an organism for Nutrient, nutritional support. Food is usually of plant, animal, or Fungus, fungal origin and contains essential nutrients such as carbohydrates, fats, protein (nutrient), proteins, vitamins, ...
, toiletries, or other scented items are placed in a bag and then raised into the air with a rope — out of its reach. The rationale is that bears, being unable to reach the food, are less drawn to campsites and pose less of a threat to
campers and their equipment.
Often this is done by tying another length of rope tightly between two trees or other tall objects. A bear bag should be at least 15 feet (4.5 m) high and 10 feet (3 m) from any vertical support. The counterbalance method, Marrison system, and Pacific Crest Trail method are a few different techniques to use when hanging a bear bag.
In recent years, bear bagging has received significant scrutiny for its ineffectiveness. In alpine environments there are often not sufficient trees and smaller trees have been damaged by ropes rubbing over bark. Bear bagging can also be dangerous and resulted in a camper's death in 2011. Bears are also effective climbers who climb trees to retrieve hung food or bite through ropes.
In many areas, such as Yosemite National Park, The Maroon Bells-Snowmass Wilderness, and Denali National Park land managers have deemed bear bagging ineffective and made it illegal.
[Bears and Food Storage](_blank)
from the Yosemite National Park
Yosemite National Park ( ) is a List of national parks of the United States, national park of the United States in California. It is bordered on the southeast by Sierra National Forest and on the northwest by Stanislaus National Forest. The p ...
official website
Product failure
Yellow-Yellow, a wild 125-pound
black bear in the
Adirondacks
The Adirondack Mountains ( ) are a massif of mountains in Northeastern New York (state), New York which form a circular dome approximately wide and covering about . The region contains more than 100 peaks, including Mount Marcy, which is the hi ...
near
North Elba, New York, figured out how to open several models of
polypropylene
Polypropylene (PP), also known as polypropene, is a thermoplastic polymer used in a wide variety of applications. It is produced via chain-growth polymerization from the monomer Propene, propylene.
Polypropylene belongs to the group of polyolefin ...
and
polycarbonate
Polycarbonates (PC) are a group of thermoplastic polymers containing carbonate ester, carbonate groups in their chemical structures. Polycarbonates used in engineering are strong, toughness, tough materials, and some grades are optically transp ...
bear canisters. Yellow-Yellow was killed by a hunter in the fall of 2012.
References
External links
{{commons category, Bear-resistant equipment
List of containers approved in the Sierrasfrom sierrawild.gov
Hiking equipment
Bears
Bags
Camping equipment
Food storage containers
Survival skills
Food storage
Appalachiantrail.org/bears