I searched and found a similar thread:
Our case is a little different. We expanded our extra-territorial "fringe" area in 1989. A junk yard was then located on a parcel within the captured area. The property owner has since expanded his lease-hold to some 44 acres, although junk cars are parked on about half that amount. We have aerial documentation and land-transfer records to affirm the expansions.
The problem is our code never forecast the open use of land of a non-conforming use, staying instead inside a structure (and allowing one-time expansion to the full structure). Not a peep about land.
Anybody have any experiences you'd care to share?