Hi Linda -nice to see you online...
 
I think Mississippi may have changed their definitions - I'm about to file 40
some site cards with the State,  following their guidelines for site status.
 Many of these fall into the late 19th-early 20th century time period.   If
anyone plans to work in Mississippi - they'd best check for new guidelines.
 Sites from the later 20th century are to be recorded with the State, but
will not be assigned site numbers at this time.  Anyone from Mississippi care
to clarify the guidelines?
 
As for the rest of your comments, I agree wholeheartedly.  Some sites have
excellent research potential, others aren't worth diddly - but that's true of
any time period.  The thought of randomly sampling Archaic sites without
taking context, site condition, etc. into account would shock many - there's
no reason to treat a late historic site any differently.