Strange Stuff That Interests Me

This is an eroded area I see  my travels. I wonder how this one area came to be eroded when the surrounding area didn't. The soil appears to be dried mud while the surrounding area appears to be leoss hills. The eroded area appears to be nearly vertical. Nothing else in the area is close to being vertical.

Any ideas? (Yes Sisty, most everyone knows I'm about a bubble off plumb).