Despite the apparent terrain complexity and disorder, if you examine a wide range of mogul runs, you will discover that, despite some variation in shape, every mogul has 6 common terrain elements:
1 Flat Top: every mogul has a top that is flat and the top is often covered with a soft pile of snow.
1 Spine: every mogul has a spine or pointed ridge line that runs the length of the mogul from the top of the mogul to the bottom of the mogul.
2 Secondary Fall Lines: on each side of every mogul spine there are angled slopes that run down to the trough on either side of the mogul. Think of these slopes as secondary fall lines because the terrain slopes down at angles that are different from the overall fall line of the mogul run and different from the slope of the mogul spine. Each secondary fall line has its own unique slope angle and the slope angle typically varies across the length of the spine.
2 Troughs: troughs run between moguls and those troughs are on both sides of the mogul at the base of the secondary fall lines that come off the mogul spines.
The photo below shows the same mogul photo from the previous page with each of the 6 terrain elements annotated.