Yes, before taking off with your ATV or "quad", you should be very familiar with the laws in the area where you plan to stop.
Here in Montana, in order for your ATV to be street legal, it must have a rear view mirror, a horn, a muffler, hi/lo headlights, a taillight, and a license plate light. An ATV that is NOT street legal can not be ridden on public roads. Numbered Forest Service roads in the back country are considered public roads. You may not ride your ATV cross country where there isn't already a track.
Out of state ATVs must go to any Fish, Wildlife, and Parks office to get a sticker, good for one year, cost $5.
Just some examples of things an ATV owner should know.