For about two years I lived in Amargosa Valley, about 20 miles from Death Valley. I worked in an underground mine that actually mined under Death Valley. So listen to me when I tell you this:

Take WATER. LOTS OF WATER. Keep it in your vehicle, carry it on you. Filters and purification tablets are of marginal value, because there is nothing to filter or purify. There is a reason it is called DEATH Valley. You will notice that almost everything out there is named after something related to Death (Funeral Mountains, Devil's Golf Course, Dante's View, etc.)

If you are going to be there in the summer, it is dry and incredibly hot (120-130F range. If I remember right the record is 134.)

Also, make sure your vehicles are in tip-top shape. The heat is hard on them, and there are several places where you are driving up hill at a 5% to 7% grade for miles. If you are driving an older car I can guarantee you that if you leave your air conditioner on, you will overheat going from Furnace Creek (elev -100ft) to Death Valley Junction (elev. approx 2000 feet)During the summer, it wasn't unusual to run across stranded cars every day on my commute to and from the mine. Put a couple of gallons of anti-freeze in each vehicle, and of course, did I mention WATER.

Also keep in mind, if you find yourself in a survival situation, and you DO find water, be very careful. Many of the so-called water holes contain water that will make you sick. There are a lot of minerals out there, and the few places that do have ground water tend to have water that is VERY HIGH in mineral content. Not sure how filters work on minerals etc. Maybe someone else here with more expertise can comment.

Other things you will really want include hat, sunglasses, bandana and lots of sunscreen, especially if you are out rock hunting all day.

Other dangers include poisonous snakes and believe it or not, single car rollovers. The roads were built in the early part of the 20th century and can be dangerous.

Having said all that, DV is incredibly scenic and it is a Geologist's dream. Hope you enjoy the trip. Just remember.

BRING WATER.