There are no grizzly bears on the Appalachian Trail, and black bears are the only type of bear that can be found in the east. Black bears are much smaller and less aggressive than grizzly bears, but they are still a cause for concern. Black bears have limited eyesight but a keen sense of smell and hearing, and even though it is rare to be attacked by a black bear, it is still possible.
Something to be aware of is that black bears know when you are carrying food, and this could draw them to you. This is why you should keep your food high off the ground where the bears can’t get to it. There are designated bear barriers where you can hang your food at a safe height. This will stop bears from coming into your space, and it will also keep your food safe from wildlife.
If you do see a bear, do not approach it. Though, you should make sure that you keep an eye on its behavior. If the bear starts to watch you or changes its path, these can both be signals that you are too close to it. You should turn back slowly and increase the distance between you and the bear. Keep watching them to make sure, but they should do the same.
If the bear is still on your trail, then you should try to change direction. Hopefully, the bear will get bored and wander off in another direction. Do not run away from the bear, as this could agitate its behavior.