These tips and rules apply for all parts of the country, but are especially useful for those states in the western sunbelt: California, Arizona, Utah, Nevada, New Mexico, West Texas and much of Colorado.
1. If you are renting a vehicle, some of your party will not be able to drive the rental car due to age restrictions. If two are over 21, they will be the drivers. If only one is of age, that one will be the only one driving the rental. Rental agencies in some states charge extra for extra drivers, too, so take that into consideration.
2. Anyone not driving has other duties to perform. You need a navigator, or map reader and a journalist. That's right, someone should write a trip journal for every day and every site visited. It can be done on a tablet or iPad, but otherwise that person should have a notebook and pen.
3. Make rest stops every hour or so, and rotate seats so that everyone gets to sit in the front passenger seat at least twice each day. The view is better from that position.
4. The first stop after getting the rental vehicle is at a Walmart, Target or any superstore with food, clothing and appliances. Purchase these items:
Medium Plastic cooler
Bottled water - 24 pack or larger
Ice (you will need to replenish as necessary)
Billed or brimmed hats for shade (Always wear it outside vehicle)
Sunscreen and insect repellent (Use both when hiking)
Sunglasses, if you don't have them
Flashlight with extra batteries (Useful if camping, or in dark areas like caves)
Inexpensive cell phone with usable minutes
First aid kit (available in the automotive department)
GPS unit (some are less than $100. Get it programmed at the store, if necessary)
5. If you haven't purchased a National Parks Pass, get one at the first NPS Visitor Center you visit. Only one per vehicle is needed, and present it whenever there is an entry fee. You never know when it might work to waive the fee.
6. Some state parks allow multiple entry to all parks with a weekly pass that you can purchase at the first park you visit. Always ask about it.
7. You should have a road atlas and individual state maps for each state you will visit. If you don't have them, state maps are free at the first rest area/welcome center in each state.
A Rand McNally Road Atlas can be purchased in advance from this website.
8. Use water liberally. Take it with you whenever you hike, and drink at least 2-3 bottles each day. Don't allow yourself to get dehydrated.
9. Stay on the marked trail at all times, and don't be tempted to go out on ledges or cliffs without railings. Many people die in our national parks every year due to carelessness and ignorance of park rules. Falls are a major reason, but confrontation with wildlife, especially rattlesnakes, is another cause.
10. Don't overdo it. Know your limits and don't attempt anything you are not qualified or comfortable with. Rock climbing and other strenuous activities are for professionals.