They advise park visitors to wear little bells on their clothes so they make noise when hiking. The bell noise allows bears to hear them coming from a distance and not be startled by a hiker accidentally sneaking up on them. This might cause a bear to charge.
Visitors should also carry a pepper spray can just in case a bear is encountered. Spraying the pepper into the air will irritate the bear's sensitive nose and it will run away.
It is also a good idea to keep an eye out for fresh bear scat so you have an idea if bears are in the area. People should be able to recognize the difference between black bear and grizzly bear scat.
Black bear droppings are smaller and often contain berries, leaves, and possibly bits of fur. Grizzly bear droppings tend to contain small bells and smell of pepper.