A Bear Bag Line is comprised of a piece of aircraft cab ling strung between trees or sometimes poles in the backcountry. Lines are generally at least twenty-five feet in the air, so as to prevent bears from accessing the bear bags and oops bags that are strung on them. There are often multiple bear bag lines in each campsite due to the large number of crews which may be camping there at one time. Multiple bear bags are often put on the same line, though it is advisable to tie the rope to different anchors for each one. If a preset bear bag line is unavailable, the bear bag rope may be stretched between two trees at the same height as a line, with the second bear bag line thrown over the first.