This leg of the journey includes a stop at the Little House on the Prairie in Kansas before the families engage in a reward challenge at a Kansas ranch, in which the fathers must compete in a hamburger barbecue cookoff, with the best three earning immunity from elimination. After a trip through a buffalo preserve in Oklahoma, there is an elimination challenge race in Amarillo, Texas.
After the families compete in a pie-eating contest as a prize challenge, they go hot-air ballooning in New Mexico. Next is an immunity challenge in which they must seat mannequins on an airplane, with the top family being flown ahead to a luxury resort in Phoenix. The bottom three families must go through an elimination challenge at the Meteor Crater in Arizona, where they must correctly identify various flying objects which are projected through the air.
Leaving the Meteor Crater in Arizona, the families head to Sedona where they enjoy a day of swimming and picknicking. They also compete in a reward/immunity challenge in which each family member is spun on a wheel, after which all the families go to the Grand Canyon; the family which completed the most spins on the wheel in a specified time gets a helicopter tour of the canyon. The remaining families then compete in an elimination challenge at the Grand Canyon Railway in which they must successfully relay a series of safe combinations.
The three remaining families stop at the Roadkill Cafe in Seligman, then visit the Hoover Dam, where they compete in a reward challenge to build a small hydroelectric generator. After everyone continues to Las Vegas, the two fastest families in the reward challenge must compete in an urban challenge to locate the fathers in the city after they have been made to disappear by Penn & Teller. The first family to locate the fathers wins a stay at a deluxe casino hotel penthouse suite.
After departing Las Vegas, the three remaining families compete in an immunity challenge in which everyone must attempt to hit targets with paint balloons while moving down a zip line. After a stop in an Arizona ghost town, the bottom two families from the immunity challenge meet in an elimination challenge in the California desert in which they must solve a physical puzzle by moving one car out of an area where several other cars block its path.
As the final two families set out on the last leg of the journey to Los Angeles, they are each given a cube. The sides depict clues to a Los Angeles landmark where another cube can be found. Once they collect four cubes, they will be able to form a picture of the location of the final challenge. There they must race to finish a cube puzzle depicting the places they have visited. But most of the pieces show them in places they have NOT been. The first family to finish wins the $100,000 grand prize.