SUPPLIES NEEDED: Bear spray.
STEPS: Always carry bear spray if you know you'll be in an area where bears could potentially be around, and NEVER leave food behind. If you think a bear might be near, talk, whistle, or make noise. If you are charged by a grizzly bear, don't run. Simply pretend to be dead. Get down on your stomach and clasp your hands behind your neck. Spread your legs apart so it is harder for the bear to roll you over. Wait until the bear leaves to get up and walk away. On the other hand, if a black bear charges you, don't run, but stand your ground. Wave your arms and shout. If possible, use a stick or throw something at it to fight back.
You can read more about how to handle bear encounters here.