Dan Wagner
Bear Canister 101
They can be cuter than hell, but can also ruin a backpacking trip in a big way if you're not smart. If heading into bear territory, you need to make sure your food and scented items are stored properly. This means using a bear canister. Bear bags are often effective, but some areas like Yosemite, Grand Teton and the Eastern High Peaks Wilderness in the Adirondacks actually require bear canisters. How to pack a bear canister can be key to a successful adventure and preventing Gary the bear from getting your goodies.

How To Pack
As a general rule, if it goes in your mouth or on your skin, put it in. This includes food, toothpaste, deodorant, lotion, lip balm, gum, bug spray, soap, medication, trash, etc.
If storing a canister inside your pack, place it in the middle and surround with items that will prevent it from shifting around. Clothes and tent rainflies work well.
Remove your food's factory packaging and repack in plastic baggies when possible. Think of all that wasted space in the last bag of chips you ripped open. Don't waste the precious space in your canister. If there's room left, fill the canister with socks, clean undies, headlamp, etc. to free up room in your pack.
If hiking in grizzly territory it's a good idea to use odor negating bags in addition to a bear canister. Zpacks and Smelly Proof both make quality bags. They're very simple and we really like using them.
Apply glow-in-the-dark tape to help with nighttime visibility. This is a little peace of mind tip that we've grown to really like. If you wake up in the middle of the night and see the glow in the dark tape moving around, Gary the bear is working it.
Bear canisters can be used as a stool so keep that in mind when packing. It's not super comfortable, but if you're looking to reduce pack contents it's an option in lieu of a camp chair. The lid can also come in handy if you need to dig through dirt or sand, but be careful not to damage the threads.
Don't leave your keys or wallet in your bear canister at night. Use your imagination with this one.
How To Carry
Under a pack lid
Inside pack
Where to Store
Store in or under shrubs or behind, under or between rocks, if possible. Use anything that could prevent a bear from rolling the canister away. Don't leave next to a cliff or water source where a bear can knock it off or in.
Best Bear Canisters For Backpacking
You'll need roughly 100 cubic inches of capacity per day for food and other scented items, so keep that in mind when choosing the size of a canister. Not storing your first day's worth of food in the canister will give you a little more room if you need it.

The BearVault BV450 is the go to for many backpackers and is approved virtually everywhere but in the Adirondacks' Eastern High Peaks Wilderness where a bear once known as Yellow-Yellow apparently figured out how to open and routinely did so. The bear died in 2012, but the area still bans its use. Its clear sides make it very helpful in finding exactly what you're looking for and has a capacity for about four days worth of food for a single hiker. 2 lbs. 1 oz., 8.7 in. x 8.3 in., 440 cubic inches.

The BearVault BV500 is the same as the BV450 but has more capacity, roughly seven days worth of food for a single hiker. 2 lbs. 9 oz., 8.7 in. x 12.7 in., 700 cubic inches.

The Garcia Backpacker's Cache is another awesome canister that is approved everywhere in the US. It's slightly heavier than the options above and finding what you're looking for isn't as easy, but it's rock solid. If you're not planning on backpacking in the Adirondacks we'd go with a BearVault option for weight. 2lb. 12 oz., 8.8 in. x 12 in., 614 cubic inches.

The Bare Box Contender is the lightest and most compact option of the bunch and great for solo backpackers on weekend trips. It holds roughly two days of food for a single hiker, maybe a little more, so it's limiting in that sense. 1 lb. 10 oz, 7.4 in. x 8 in., 275 cubic inches.
Where Bear Canisters Are Required
Big Bend National Park: all backcountry areas
Canyonlands: Salt Creek campsites, Salt/Horse Zone in The Needles District, and Peekaboo campsites from March 15 through November 30
Denali: within Units 1-21 and 23-43
Eastern High Peaks Wilderness Area: required between April 1 and November 30
Gates of the Arctic: most areas
Glacier Bay: most areas
Glacier National Park: required in the Nyack / Coal Creek Camping Zone
Grand Teton: all areas unless food lockers are available
Inyo National Forest: required in some areas
Lassen-Volcanic National Park: all backcountry areas from April 16 through November 30
Maroon Bells–Snowmass Wilderness: all areas (read more)
North Cascades: some areas from June 1 through November 15
Olympic National Park: required in most backcountry areas
Rocky Mountain National Park: required in areas below the treeline between April 1 and October 31
Sequoia-Kings: required in the Dusy Basin, Palisade Basin, Rae Lakes Loop, North Dome, Rock Creek, and Pear and Emerald Lakes areas from May 1 through October 31
Sierra Nevada: required in some areas
Yosemite National Park: all backcountry areas
Bear Canister Alternatives
Bear bags aren't approved in some national parks and wilderness areas, but offer a great lightweight alternative to those that do. These options are hung from a tree branch with their integrated high tensile strength cord. 15' off the ground, 10' from the tree's trunk, and 100' from camp in black bear territory or 300' in grizzly and brown bear territory. It's also recommended that an odor barrier bag is used as a liner when hanging in grizzly or brown bear territory.

The Ursack Major bag is bear resistant, but not critter resistant. Its fabric blocks large teeth and claws but can allow smaller teeth to penetrate. Think marmots, mice, racoons and other small animals. It comes in 10L (610 cubic inches), 15L (915 cubic inches) and 30L (1,830 cubic inches) capacities and weighs in at 7.6 ounces.

The Ursack AllMitey bag is made of the same material, but is also laminated with Kevlar giving it both bear and critter resistance. It comes in 10L (610 cubic inches), 20L (1,220 cubic inches) and 30L (1,830 cubic inches) capacities and weighs in at 9.5 ounces.