Season 6 opens with a qualifying round in Venice Beach, Cal., and features obstacles such as the Slack Ladder, the Jumping Bars Into Cargo, and the Cannonball Alley. Contestants include Olympians Susan Francia and Kate Hansen.

Competition in Dallas includes Tilting Table, Ring Toss and Swinging Frames.

New obstacles in St. Louis include Rope Junction Into Cargo, Double Tilted Ladder and Crazy Cliffhanger. Competitors include X-Games athlete Kevin Robinson, motorcycle racer Domonic Anderson and Nick Groff ("Ghost Adventures").

A qualifying round in Miami featuring the Dancing Stones, the Downhill Pipe Drop and the Mine Field. Contestants include wakeboard champions Rusty Malinoski and Shaun Murray; Olympians Fabien Lefevre and Preston Griffall; and former Las Vegas finalists Joyce Shahboz, Drew Drechsel and David "Flip" Rodriguez.

The final qualifying round takes place in Denver and features the never-before-seen Cat Grab and Spikes into Cargo obstacles. Contestants include former competitor Brian Arnold; mixed-martial-arts fighter Michelle Waterson; Bull Bullard of the Harlem Globetrotters; BMX champ Morgan Wade; and fitness blogger Drew Manning.

The Top 30 contenders from the Venice Qualifier compete in the Venice Finals course, which includes obstacles such as the Salmon Ladder, Cannonball Alley, Body Prop and Spider Climb.

The Top 30 contenders from the Dallas Qualifier compete in the Dallas Finals course, which includes obstacles such as the Salmon Ladder, Swinging Frames, Pole Grasper and Spider Climb.

The Top 30 contenders from the St. Louis Qualifier compete in the St. Louis Finals course, which includes obstacles such as the Salmon Ladder, Rumbling Dice, Crazy Cliffhanger and Spider Climb.

Top competitors from the Miami qualifier face the finals course, which includes Salmon Ladder, Floating Stairs, Mine Field and Spider Climb.

Competitors face the finals course in Denver.

Highlights from the season focus on the competitors that provided the most impressive or entertaining runs through what many consider to be the world's most difficult obstacle course.

Top finishers from the regional finals tackle stage 1 of the four stage finals course in Las Vegas.

Top finishers from the regional finals continue to tackle stage 1 of the four stage finals course in Las Vegas.

The National Finals in Vegas continue with stage 2 and beyond.