Planning a trip out west

I am looking for information based on rider experience to help in planning a trip to Wyoming, Montana and British Columbia next summer. Anyone who has information on riding in these two states and BC please share them with me. I’ve been out West numerous times but never on a off road based trip. The Big Horns are a must and I’ve snowmobiled around Yellowstone but really need solid ATV info. Thanks, and looking forward to hearing some solid advice. Also I know there is a ton of great riding in Colorado and Utah but they are not in the plan this trip.