When you encounter any type of bear or bears including a grizzly bear never run.
If you run then the bear might decide to run after you and see you as a threat and attack you.
Never make direct eye contact with the bear and wait to see if the bear is not approaching you and if the bear is not approaching you then walk away from the bear slowly while avoiding eye contact with the bear.
If you cannot get away then stand still and if you have too then try to fight back but try to get away if possible and never yell or scream even though you may be tempted to do so for help.
If you have some pepper spray then spray the bear with pepper spray if it charges you or if you have a gun then shoot the bear if it's trying to come at you.
I always keep a gun on me whenever I'm in an area where bears may be present but I've never had to use it on a bear or anything yet but it's there just in case.
Just don't startle the bear and keep your distance from the bear and they will usually leave you alone.
Pepper spray at least is a must if you're going into areas where bears are and get some bear pepper spray.