As the name says four wheel drive is required. There are several steep inclines on loose gravel and a variety of washes and rocks. Otherwise once you arrive in the area it should be a relatively an easy find. You will be looking for a standard ammo can.
CAUTION: This cache is heavily guarded by dragons, dinosaurs, yetis, wild ninjas, angery robots, slime monsters, aliens, coyotes with Acme laser cannons, gorillas with uzies, angery house wives, zombies, psycho clowns, sharks, injury lawyers, parranahs, crocodiles, cyclopes, demons, ogres, trolls, United flight attendents, and worst of all, politicians!