Maybe. Every park I've backpacked in though I've called the ranger station ahead of time to ask questions about and I always ask about carrying. The response is always the same, "I never go out unarmed".
I've had run ins with black bears a few times in Wisconsin and once in Oklahoma. one ran right up on me, looked at me funny, barked, and that was it. Another time we were following one down a trail, never saw it but kept finding fresh footprints and bear shit. It just kept heading away from us, we eventually turned and set up camp.
I've also been out when an active wolf pack was in the area, and that was actually awesome to listen too all night.
Wild boars are actually my concern when backpacking though, they are the reason I carry. For bears I just put ammonia out around camp now, they stay away.