In the blink of an eye, I went from sitting in the leather-lined Land Rover LR3 to dangling from a rope and harness over a river in Bolivia. Below me was a muddy sandbar surrounded on all sides by swift-moving milk-chocolate water. Sitting in a kayak on the water was one of Land Rover's talented logistics scouts who moonlights as a competitive river kayaker. I asked the gentleman holding my safety rope how I was supposed to get back to the LR3 on top of the bridge. Jump into the raging water, he said, grab hold of the rear of the kayak, and paddle-kick hard, navigating the current to reach the shore. So much for keeping the mud out of my bathing suit.

This was day three of a four-day reconnaissance trip deep into the South American country of Bolivia where Land Rover will hold the third leg of its 2006 G4 Challenge. The G4 event is a global adventure race open to entrants from 18 countries (one from each), designed to challenge a competitor's physical abilities with mountain biking, climbing, orienteering (finding your way to a specific spot with a primitive map and a compass), and the aforementioned river kayaking and abseiling, but also to test their off-road driving skills, wits, character, and cross-cultural social skills. Would-be competitors have been participating in national and international competitions for the last year to make the cut.

The 2006 event will travel to two continents and four countries. In addition to Bolivia and neighboring Brazil, competitors will drive Land Rovers and Range Rovers in the Southeast Asian countries of Laos and Thailand.

To prove just how intricate this race is (and the preparation that takes place behind the scenes), Land Rover invited us to join its already-in-progress "recce" team as it planned one of the four legs of the Challenge. The team spends months at each location scouting routes, developing on-site competitions, working with local governments for permits, and learning local cultures so they can find a way to integrate them into the event.

I met up with the recce team in the tropical climate town of Santa Cruz where I was briefed on what the next few days in backcountry Bolivia would be like. Our plan was to drive one LR3 and four Defender 110s on a 700-mile round trip from Santa Cruz high into the Andes Mountains, and then back via an alternate route.