If a Game Warden or other Peace Officer sees that a violation has occurred in his presence he can act. Other wise he must conduct an investigation, gather evidence, interview witnesses, swear out affidavits, present them to a judge or justice of the peace in order to enter onto private property to further investigate a complaint. A game warden or peace officer has no special priveledge to tner onto private property unless he has knowledge that a crime or offense has occurred. But, any peace officer or game warden can not conduct "Fishing Expaditions", randemly search for some violation, with out resonable suspicion.
Now, its different if you are driving down the road and a deer hoof is clearly seen poking out of the back of the truck. That is prima Facia that there is clearly what appears to be a dead deer in the back of that truck and being as how it is in plain view the game warden, or peace officer, can in fact investigate further because of the plain view doctrine.
We can go on and on and on about what if? or Coulda, shoulda, woulda, but in the end it boils down to this: Unless you have prior permission to enter onto private property, and it should be writen permission, then you can not enter onto private property and NO LAW ENFORCEMENT OFFICER CAN GIVE YOU PERMISSION TO ENTER ONTO PRIVATE PROPERTY FOR ANY REASON UNLESS THE LAW ENFORCEMENT OFFICER IS THE OWNER OR THE OWNERS AGENT OF THE SAID PRIVATE PROPERTY. Pretty much the end.