ORIGINAL: Wingbone
I'll give you my take on it. Ridges are self explanitory. A hollow would be the low area between ridges. A ravine is a narrow steep cut into a ridge. A saddle would be an area of ridge topsignificantlylower than the rest of the ridge, thus making it easier to cross.
Good job, Wingbone!
Chux, you didn't ask what a "draw" is!
But anyway, it's a creek bottom, maybe not quite as steep as a ravine!