Among the frontiers largely open for exploration are the western deserts and mountains. One might think of the desert as a boring place with nothing to see. Au contrair, mon ami! There are many interesting places to explore and things to discover.
Much of the west was originally settled for mining. There are plentiful supplies of many precious metals and minerals, and at the time it was easy to find a spot and start digging. Some proved fruitful, some not so much. Because of this there are mines hidden in many remote areas. Areas one may be able to access with an ATV.
First, however, it must be pointed out that mine exploration can be extremely dangerous! You should never go into a mine without proper training and/or a guide, permission from the property owner, and someone outside who knows exactly where you are and what you're doing. In many cases, even if you are well trained a mine is too dangerous to enter, so learn to recognize the warning signs.
If all the proper safety criteria are met, and permission is obtained, then go forth oh intrepid one. Sometimes half the fun is the ride. You might have to go up a little-traveled canyon, or into a seldom visited area, so there's a good chance you'll see something interesting out there. Make sure your ATV shocks are ready for any sort of terrain as well.
When it comes time to go into the mine, be prepared with all the right gear. A good flashlight, (and maybe a backup in case you drop it), a hard hat, and rope are the most basic. Watch for signs of wildlife, if something has moved in, you don't want to disturb their home, especially if there are young animals there. It can be fascinating to see the way the mines have been cut, particularly older mines where more archaic tools were used.
Occasionally you may be the first one in some time to visit. You might find something historic like the end of the dig where the miners carved their names. There may even be old equipment inside. It's important never to take anything you might find without express permission from the property owner, be it private property or government owned. Even taking things from public lands can be prosecuted as a felony.
Whatever you find, keep track of it. Join a group or message board with others who share your interests. There are many groups who go together to visit and explore these off the beaten path locations. So get your ATV shocks ready for an out of the way ride and go exploring!