The event challenges 30 teams of three ultrarunners - running together for the duration, not in a relay - to tackle an unimaginable traverse of Southern California deserts and mountains. The route covers 81 miles (130km) non-stop from below sea level at the shoreline of the Salton Sea, across, up, and over Anza-Borrego Desert State Park, to the top of Palomar Mountain with a dramatic view of the Pacific Ocean.