A couple of suggestions. Late summer is a good time to photograph bears since they are fat with thick coats. In the spring or early summer, adults can look a bit ragged. But of course, that's when you see the cubs.
For black bears, the Vince Shute Sanctuary near Orr, MN is a good location. I was there for several days a couple of years ago. I was within a few feet of very large adult black bears but still safe. It's a low cost / low budget operation but quite unique. Several NANPA members offer tours there.