I would like to know what is included in the grandfather clause for
wisconsin sportsman's clubs and how would a club lose the grandfather
clause such as maybe logging an existing forest on the property or
taking down a large hill that acts as a noise buffer to the neighbors
in order to level off the parking lot.  In other words does changing
the landscape of the land the club owns and thus causing the neighbors
to be directly affected by gunshots etc. cause the grandfather clause
to be lost by the club?

While this is not an answer to your question it may in fact give you a
direction to go in to attain an answer. Wisconsin has(as do many
states) a Lawyer Refferal Service that  find an attorney with
knowledge in the area you are seeking info, and gives you a consult
for a nominal fee ($20>00 for the first 1/2 hour i believe)
here is the state bar refferal service:  
http://www.wisbar.org/bar/sblris.htm
here is another similiar service:  
http://www.legalexplorer.com/lawyer/lawyer-talk.asp


I hope this helps