More info on the terrain: that apparently resides on the #2 data card
and is a separate update process that comes from Garmin rather than
from Jeppesen. Cost is expected to be $35 per update or $195 for 12
monthly updates.

Mountains don't move much, but I suppose there are always towers.
However, I wonder about the value of terrain in the midwest. I suppose
if one were in an emergency situation it could be handy to see where
the nearest antenna farm is.