You need a reasonably reliable 4WD vehicle, good off-road tires, some recovery gear, a way to safely carry water and cook, and you are good to go.
Jakob Schiller, writing for Outside Magazine:
You may have noticed: our wild places are getting crowded. Last year, 331 million people visited the U.S.’s 59 national parks—58 million more than ten years ago. Which means that if you want solitude, you’ve got to work for it.
One way is through overlanding, which, loosely defined, is off-road camping. Some head out for years on end, but the majority take their rigs on weeklong jaunts. “It’s about using sturdy vehicles to explore, whether 100 miles or 10,000 miles from home,” says Roseann Hanson, founder of Overland Expo, a semiannual gathering of the tribe in Flagstaff, Arizona, and Asheville, North Carolina. The practice has long been popular in places like Australia and South Africa, but it’s gaining traction in the U.S. Rooftop tents are popping up in Brooklyn as well as Bozeman. And 12,000 people turned out for this year’s OE in Flagstaff, 20 percent more than last year.
Much of the gear is overkill, but a few select items can help the exceptionally itinerant find the space they need.