Benches can be as small as a bathtub size niche in a mountain side. Elk like to be comfortable when they bed down, just like you and I. A good example of a manmade bench would be a logging road cut into a mountain side. These old roads that have been closed for many years can find elk bedded on them in the colder temperatures soaking up some sun rays. Elk love benches as laying down on a slope is uncomfortable.
Another area is the knob of fingers. Many times a finger ridge will slowly drop in elevation as it runs away from a main ridge. It will level out then drop off dramatically. The point it which it levels out is a great spot to catch bedded elk.