Throughout North America, when American black bears (Ursus americanus) enter backcountry campsites to obtain human food, undesirable and potentially dangerous incidents occur. This problem is minimized if overnight users of the backcountry (‘backpackers’) carry their food in bear-resistant canisters or use metal storage lockers. I surveyed 242 backpacking groups in Sequoia and Kings Canyon National Parks (SEKI), during the summer of 2003. Voluntary use of canisters or storage lockers was high (91%). Users' most frequent explanations for canister use were: to protect food, to protect themselves, to keep bears wild, and convenience. Survey results suggest that losing food to a bear also encouraged the subsequent use of a canister. Availability of rental canisters at the trailhead facilitated this storage option. A minority of backpacking parties (9%) persisted in using food hanging (a method easily overcome by SEKI bears), explaining that they had always stored food that way or that canisters were too small and heavy. This user group is sufficiently large that bears continued to obtain human food, and nuisance behaviors persisted. To ensure that backpackers universally store food in a way that it is unavailable to bears (canisters or lockers), regulations may be desirable.