a system like the new UrsaLite Bear Bag Systemsuffice. I was under the impression that at this time, one needs a bear cannister, particularly along certain sections of the trail...just curious, because this looks like a very ultralight alternative.
Here is the latest info I've seen on this topic:
In Yosemite and Sequoia and Kings Canyon National Parks, the following models meet bear canister regulations as of 2010: Garcia Backpacker (model 812), Counter Assault Bear Keg, Wild Idea Bearikade Weekender and Expedition MKII (and the Scout in Sequoia and Kings Canyon), Bear Vault (models 110b, 200, 250, 300, 350, 400, 450, and 500), and Bare Boxer (Contender and Champ models). The Purple Mountain Engineering Tahoe bear canister is also allowed, although this product is no longer in production or available for purchase. National forests and wilderness areas in the Sierra follow similar guidelines.
you won't get a permit for the JMT either in Lone Pine nor in Yosemite unless you use a bear canister. They are mandatory in the Whitney zone, most of Sequoia, in all of Yosemite, parts of Kings Canyon, and highly recommended in the wilderness areas in between.