Cuz... WOW!!
I'm a day late and a dollar short on this thread, but once reading it I immediately looked up some laws. Two links that popped up were these:
http://fishandgame.idaho.gov/hunt/rules/bg/law_new.pdf
http://www3.state.id.us/cgi-bin/newidst?sctid=180700008.K
From what you say, you have the right to tresspass these guys as the legal representative of the land owner. Not sure if that land is marked up with signs and floresant paint, but I think it needs to be to be completely legal for trespass. One part in the Idaho laws states that it is illegal to interfear with a legal hunt, so if these choads did indeed run off the game, then that would be a violation, unfortunately hard to prove.
I was totally bummed when I read this thread. Makes me want to come up and sit on your land when you are out working as a "legal representative"...