Very good topic. I have hunted CO on semi- guided hunts. This meaning some days I'm hunting with the guide, others on my own. I have used GPS to mark trails back to areas I intend to hunt. We talked about it, and they had no problems with it at all. The areas arer public land, but access from the ranch is by far easier than coming in from the other side off BLM land.
On occasion we would see or run in to other hunters that did pack in. Its frustrating, only in that after a good amount of hiking there was someone already hunting in the area we planned. We moved to anothe area.
Its really all about common courtesy. I fish on a large body of water( Saginaw Bay) for walleye. Is this really any different than going on a charter, and learning from the captain areas to fish and lures to use? Not really. Now, I could sit in the marina and follow the next charter boat out of the marina, and set up and troll right behind him all day. This would be quite rude. Same with popping up inthe middle of an area an outfitter is hunting. Now if I am inthe same area, and find they are not there, then I see no reason that there is anything wrong.
In hunting, or fishing, the game or fish are not always inthe exact same spots every time. Too many variables. I may know of a particular bench that holds elk, with a water hole or wallow that is hot at times. Doesnt mean that I would sit right next to someone elses set-up, although at some point in a hunt, I may work that area.
I have heard of guides, who have the guiding permit for a cerain area get downright threatening of hunters who "encroach" on that area. Some will tell non-clients that they are trespassing on private land when in fact they are on public land. If this happens, I would contact the warden. Study your maps, and know where you are. KNow the laws of the state you are in. Trespassing is a serious violation in most western states. But ifyou are on public land, you have every right to hunt there.
Be courteous of other hunters, and don't piss in their wheaties.