Fort Trenholm, a massive earthen fort near
Charleston, SC, has such provisions in its
MOA and CRMP. The CRMP details the
maintenance activities, the prohibitions,
etc. and limits the number of visits and the
type of on-ground activities and where they
may take place with annual inspections to see
what problems may arise.

I have seen 4-5' high earthworks with good
definition reduced to 1.5' high amorphous
linear blobs due to kids on bicycles.
Planting poison ivy or cactus is a step
recommended which every time draws chuckles
until the powers that be understand what the
problems are. I know of one earthwork which
has poison ivy (grown opportunistically) and
an observation walk built over it
specifically to stop damage.

Lyle