Grylls parachutes into the Sierra Nevadas, simulating the situation of the hundreds of hikers who become stranded there each year. Equipped with a knife and a canteen, Grylls travels through the alpine, woodland and chaparral areas of the mountains. He unsuccessfully tries to tame a wild horse, and eats a live snake. Using techniques gleaned from the Mono Indians, he brushes his teeth with a manzanita leaf. Most of the ground he covers is traversed by river, using a raft held together by grape vine.
