Riding ethically on the off-road trails in Wyoming is just good common sense. There aren't a set of ethical laws and there are no ethics police to come enforce these rules, but they should be followed none-the-less.
When you're riding your ATV, commonsense will tell you if you come upon private land, leave it as you found it. That's a good ethic in riding your ATV. Another common occurrence is if you come upon forest or game animals, don't go out of your way to frighten them or chase them on your ATV, that's another good ethical riding skill.
Some other good ethics to observe out on the ATV trails are :
*Do not go trailblazing on your ATV and otherwise damage the land. If the ground is extremely muddy or wet, find a way around that area, riding your ATV directly through it can damage the vegetation around the area substantially.
*Be aware of other riders. This includes not only other ATVers, but motorcyclists and horseback riders as well.
*If a horseback rider is approaching you from either direction, pull your ATV over and let the horse and rider pass your ATV. The engine may not spook all horses, but if someone got thrown from a horse and was badly injured, you could be held liable. The ethical thing to do is err on the side of caution and let the horse pass your parked ATV.
*Volunteer when you can. ATV trails need lots of maintenance to stay fresh. Periodically ATV trails need to be closed so the land can reclaim itself and new ATV trails opened. Help your local forest agency or private ATV riding trail facility if you are able.
Treadlightly has developed a large amount of information for riding your ATV ethically. Learn all you can and have a great time riding your ATV and knowing you're doing it responsibly.