It cannot be said too often that wild animals are just that and should not be approached unless with a qualified guide or similar. There are many incidents each year involving people being hurt and even killed. Virtually all of them could have been avoided.
If you are going into an area where animal encounters are possible get information on how to behave. Watching animals in the wild is very satisfying and is encouraged in many areas but the animals' 'wildness' must be respected. Large animals such as bears and bison must not be approached as they can be quite unpredictable and are potentially very dangerous.
Feeding wild animals is prohibited as it encourages them to keep approaching humans and often if they persist they have to be destroyed. This is tragic as it is our fault when this happens! You can usually see plenty of wild animals when keeping to the authorised areas.
When in campgrounds where there are warnings of bears in the vicinity, follow the rules strictly as bears can destroy tents and cause a lot of damage to vehicles in their attempts to get to food. Thus you never have food or dirty dishes in tents. If there are no bear proof bins to store food it is usually recommended you tie it to a rope slung over a branch and haul it up at least 10 feet off the ground. Check the rangers' advice and be very careful.