Season 4

People from the Southwest compete for a chance at the world's most difficult obstacle course.

People from the Southwest compete for a chance at the world's most difficult obstacle course.

The top 30 finishers from the Southwest qualifying round take on an even more challenging obstacle course to advance to the national finals.

Midwest competitors try to qualify for the national contest.

Midwest competitors try to qualify for the national contest.

The top 30 qualifiers compete for a chance to move on to the national finals and tackle a harder course in hope of getting the $50,000 prize.

Athletes from the Northeast compete.

Athletes from the Northeast compete.

The top 30 Northeast finishers take on a more challenging course.

Contestants from the Northwest compete.

Contestants from the Northwest compete.

The top 30 Northwest finishers compete.

Competitors from the Midsouth region.

Competitors from the Midsouth region.

The top 30 Mid-south competitors compete.

Athletes and everyday people compete for a chance to take on the World's Most Difficult Obstacle Course.

Athletes and everyday people compete for a chance to take on the World's Most Difficult Obstacle Course.

The top 30 Southeast finishers compete on a more challenging course..

One hundred competitors attempt the most-difficult obstacle course.

Stage 1 of the most-difficult obstacle course continues.

Stage 1 of the most difficult obstacle course continues.

Stage 1 of the 8 obstacle course will challenge even the most skilled competitors.

Top finishers challenge Mount Midoriyama.

Ultimate challenges including the Spider Flip and the Double Salmon Ladder.

Previously unseen footage includes top finishers from preliminary rounds tackling a challenging obstacle course.

Competitors face a challenging obstacle course in hope of landing a spot in the finals.

Top contenders tackle a challenging obstacle course in hope of moving to the final round.

Competitors face a challenging obstacle course in hope of landing a spot in the finals.

Athletes face the eight obstacles of Stage 1 in Las Vegas.

Finalists take on a four-stage course. Challenges include a "jumping spider" and a "spinning bridge."

Athletes compete in the finals in Las Vegas.

Top finishers from the regionals advance to the final round.