Eco-Challenge: The Expedition Race was a multi-day expedition length adventure race in which teams of four competed.

Eco-Challenge was created by Mark Burnett. inspired by an L.A. Times article about Gerald Fusil's Raid Gauloises adventure race in Costa Rica, Burnett formed a team and competed in two Raid Gauloises events. Although his teams did poorly, Burnett decided to create a similar race in North America. When the race went international, Burnett purchased the rights from Fusil and set out to make the Eco-Challenge the world's premier adventure race.

Each team comprised a mandatory mix of both men and women, racing non-stop, 24 hours a day, over a rugged 300-mile (500km) course, participating in such disciplines as trekking, whitewater canoeing, horseback riding, sea kayaking, scuba diving, mountaineering and mountain biking. Teams originally consisted of five members, but the team size was reduced to four members early in the event's history.