IF YOU SEE A BEAR THAT IS CLOSE OR IT DOES SEE YOU...
STAY CALM.
Most bears don't want to attack you; they usually want to avoid you
and ensure you're not a threat. Bears may bluff their way out of an encounter by charging and then turning away at the last second. Bears may also react defensively by woofing, growling, snapping their jaws, and laying their ears back.
BE HUMAN. Stand tall, wave your arms, and speak in a loud and low voice.
DO NOT RUN. Stand your ground or back away slowly and diagonally. Back away slowly, never run! Bears can run as fast as a racehorse, both uphill and downhill.
Talk calmly and firmly. If a bear rears on its hind legs and waves its nose about, it is trying to identify you. Remain still and talk calmly so it knows you are a human and not a prey animal. A scream or sudden movement may trigger an attack. If the bear follows, STOP.
IF A BEAR IS CHARGING... Almost all charges are 'bluff charges'.
DO NOT RUN. Olympic sprinters cannot outrun a bear, and running may trigger an instinctive reactions to 'chase'. Do not try to climb a tree unless it is literally right next to you and you can quickly get at least 30 feet up.
STAND YOUR GROUND. Wave your arms and speak in a loud low voice. Many times charging bears have come within a few feet of a person and then veered off at the last second.
IF YOU HAVE SURPRISED A BEAR AND ARE CONTACTED OR ATTACKED...
Play dead. Struggling will encourage attack. Lie flat on your stomach, or curl up in a ball with your hands laced behind your neck. Lie still, and be silent. Surprised bears usually stop attacking once you are no longer a threat (i.e., 'dead')
IF YOU HAVE BEEN STALKED BY A BEAR, DON'T PLAY DEAD - FIGHT BACK! First - try to escape, preferably to a building, car or up a tree. If you can't escape, or if the bear follows, use bear spray, or shout and try to intimidate the bear with a branch or rock. Do whatever it takes to let the bear know you are not easy prey. This kind of attack is very rare but can be very serious because it often means the bear is looking for food and preying on you.
Bear Spray?
Effectiveness is not guaranteed!
Recent research indicates that bear spray can be effective against some bears when used properly. If you plan to carry it, be aware that wind, spray distance, rain and product shelf life can all influence how well it works. Carefully read directions on the can prior to your trip. The best way to live safely with bears is to avoid contact with them.
(This material sourced from Government Web pages on the subject.)