Mike, one problem you've got, before you even start, is your characterization of your request, your hobby, etc.... You call it "... digging the landowners yard up.... " Now I'm sure you wouldn't go using those exact words in front of them, when asking, but still, there mere fact that you think of yourself in those terms, is going to color your image, to begin with.
I have heard the same thing when it comes to this topic as to public parks, schools, etc.... Someone will say "gee I don't think they want, or allow you, to 'dig up' their school ... park, ... etc....". The problem with characterizing it in that way, is the connotation it implies. "Dig up" easily implies leaving a mess, holes, shovels, etc... right? In other words, it implies the
end result, right? But if you leave no indication of your presence, well then, I would characterize it as "digging up". If you think of yourself in damaging/destructive terms, (even if you don't intend to use those terms in front of yard owners) then your odds of getting to hunt anywhere, diminish. Because no, there are few yard owners that if you approached them and said "can I dig up your yard?" are going to say "sure, by all means, help yourself".
If you use precision retreival techniques, with minimal impact, and leave no trace, then .... let's call it something else beside "digging up the yard"
