I definitely agree that bear canisters are a more practical go-to for this area than the bear bags. My reasons for this decision is experience from one time up there, we hung our bags, and another time we used the bear canisters.
Despite their weight, the canisters were the more convenient of the two because we didn't have to scout out hanging trees, or stumble out just before bed and after brushing our teeth to re-hang the bags, not to mention a few younger Scouts kept needing to get back into the bags long after we put them up (I recognize this won't be a problem you'd encounter on this trip)
When I backpack, I prefer to strike camp as quickly as possible, just walking out to the cans and stuffing them into our packs was a lot simpler than bringing the whole rig down.
Finally, they make a comfortable stool. Throw a fleece on top, and they're actually kind of nice.
Additionally, a small backup water supply kind of pays for itself. A few times in the sierras, once we got above the treeline water was a lot more scarce that we anticipated. If your map says you'll be pretty high up on a given leg of the day's hike, it might be worthwhile to stock up an extra liter or so of water on the off chance.
As a consideration, I'd like to advocate those heavy-duty contractor bags as pack liners in place of the compactor bags. They might weigh a gram or two more than most of the thinner bags, but that robustness is an asset worth considering.
I've long used one as a pack liner, paired with a reusable Zip-tie from an auto parts store. I like them because they're rugged and big, which makes them aptly suited to standard-issue backpacker multitasking, here are some of my favorite uses:
- An emergency poncho that can cover you and your pack without the pitfalls of typical rain ponchos (the open sides and gaping hole in the top)
- Weatherproofing for your bear bag that can shrug off poky branches or less-than-gentle falls to the ground.
- They can use used as a tourniquet, or to build a rugged splint with some sticks and duct tape.
- Wrapping for your gear while fording creeks and streams
- a "Gear bivy" for those times your pack has to live outside in the tent vestibule, or as extra waterproofing for taco camping.
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