Generally the first thing a Game Officer asks when they contact you is "Are you hunting or Are you fishing" If you say " NO" then they are pretty much left standing there with no grounds to ask you any further questions. If you are asked " Why are you carrying a pistol then? " Simply respond by saying "Because lawfully I can". They can ask for identification just to be certain you are not a convicted felon and that's about it. So be kind, show them your ID let them run your name and thank them for their concern and move on. If you are carrying a rifle and you are contacted regarding Hunting, you can simply state you are fearful of being attacked by Bigfoot or the drug cartel and you carry the rifle for self protection, there is really nothing they can do but perhaps think that you are a nut job and hope they can get out of the area in one piece. Just don't be a smart ass to them, be polite and courteous and thank them for their concern. They have to ask you if you are hunting or fishing so they can take the next step because they are fishing.
You do not need to have a hunting license to carry a firearm in the woods or desert as long as you are NOT pursuing any type of game animal or game bird.
Let them do their job, you be professional and they will likely return the favor.
I would add this, if you are not Hunting or Fishing, there is no obligation for you to provide ID to a game agent, even if you are open carrying. But if they suspect you are hunting or fishing and it is their professional opinion that will be the decider, then it is their call so tread lightly.
You may need to stop so they can determine if you are hunting and or fishing and or participating in an outdoor recreation. But the burden of proof is on the Officer.
Now that being said, if you antagonize too much, it may end up costing you a defense attorney retainer to prove you were right.

As FALFire said, be polite and it will turn out all right.