The black bear, the smallest of the three North American species of bear, actually comes in many colors, ranging from bluish-black to brown. In the past, visitors to national parks sometimes fed the black bears and the animals occasionally frightened a tourist by aggressively approaching them for more food. When left alone in their own habitat, however, black bears are shy and avoid people. Visitors are forbidden to feed them now, so the bears have retreated to the back country where they lead an elusive existence in forests ranging as far north as Alaska and as far south as Mexico.I have spotted black bears on many hiking expeditions, says artist Rod Frederick. I encountered this full-grown male one day in the lingering snow of early spring in the Cascade Mountains of the Pacific Northwest. I turned the corner and there he was. Because bears have notoriously bad eyesight, it took a moment before he sensed me. When he did, he turned and ran. Seeing him so close was an exhilarating experience.