I also highly recommend carrying pepper spray for bears or any other predators one might encounter. Several years ago I began riding a bike for exercise, sometimes doing so while it was dark such as late night or early morning. It amazed me how many folks have big dogs like Rottweilers and Chows that are left to run loose. I even had a couple of mutts, one huge and another much smaller, try to encircle me to attack while running one afternoon.
Needless to say I began to carry a cannister of pepper spray give to me by my brother who was in law enforcement at the time. I was forced to used it on several occasions and found it to be very effective. On one occasion it was dark and I could hear a dog running after me, I waited until it was so close I could feel it's breath and hear it huffing as it tried to get close enough to bite. At that point I pushed the button of the can already in my hand and blasted the dog fully in it's muzzel at which point the dog instantly retreated. I wasn't sure how big or what type of beast this was so the next day I rode back by the same house at which point a full grown chow began to come out after me. As the dog got close I held up the pepper spray. Upon seeing the had with spray in it, the god instantly retreated to the safety of it's owner's front porch and quit even barking.
It's important to obtain a sizable can of spray, not one of those little "purse size" with a fraction of an ounce and also I am for the higher concentrations of Capsascium (sp?) . It is also important to have the can readily accessable, in hand if a likelyhood of threat is evident such as sound or evidence of a bear nearby, approaching, etc. Last but not least, try the spray out if possible to become familiar with the pattern and distance of the spray (some spray a fog others a stream). It could be very easy if you are not used to or familar with the spray, to panic and empty the can before the bear, dog, threat...is close enough to be affected and repelled.
I agree Rusty, my first thought was if anyone of those folks had spray and had used it this situation would never have become as serious as it did. I have even wondered if the park service might possibly be able to use pepper spray to retrain some of the pesty bears so that they would avoid future human contact