Grady and Bo are dropped into separate locations of a Colombian jungle.
Grady and Josh confront the dangers of Croatia's Velebit Mountain.
Grady and Josh battle snakes, mosquitoes and dehydration in Nicaragua.
Grady and Josh face punishing conditions in Bulgaria's Rila Mountains.
Shipwrecked, Grady and Josh seek solutions for food, shelter and water.
Stranded in the Peruvian Andes, Grady and Josh battle altitude sickness.
Experts face Wyoming's Bighorn Mountains in the dead of a brutal winter.
