Discussion: Was that at Great Seal?

or somewhere else? If Great Seal, I'd guess there is a good chance the map wasn't 1:10.

Yes, it was Great Seal. A wonderful venue, but needs a good map. A common technique used there, and also at Tar Hollow, is to add a gully symbol whenever there is a re-entrant in the terrain that doesn't show up in the contours. But some of these gullys are really just reentrants.