In the thick stuff, you're probably going to hear them more than see them. Brush rustling (eating berries), stump ripping (looking for larvae), bark tearing is all in their agenda. Also when glassing, look for movement in the brush and not so much as trying to spot a "black spot". Even when glassing you'll see brush moving usually before you see the bear.
When bears are on a food source, it's like a buck in the rut. It's the only thing on their mind, and they get a lil' stoopid and only focus on what they are doing. But stay upwind of them, as they have exceptional smellers.
Gary
