Yeah it's probably stealth land. That saddle is about a mile wide on the map, and the bottom is probably shallower than it appears on the map.
Next time you come in, enable your external camera, and look at the bottom as you come in, see just how deep it actually is. I don't know if there is a field there at all, but you might have also hit a mine.
Post a few screenies if you get a view of something good.
