Does anyone know the artist who paints blk/wht images behind birch trees?

You're probably thinking of Bev Doolittle, who is very well known for a style called "camouflage art." When you first look at her paintings, you see the obvious image -- an indian in war paint sitting on a horse in a birch tree forest. Then as you look more closely (usually more slowly), you see the other indians and horses "hidden" in the background. She also does wonderful landscapes with images of animals hidden in them. Very talented painter. Google "Bev Doolittle" for her website.