"Look," Holtz exclaims, "it's not a real canyon. It's just a matte painting!" (Tap, tap, tap.)
Actually, it IS real. From the Desert overlook at the canyon's southeast rim, Dr. Holtz interprets the geology of the Grand Canyon. If you look carefully, the Great Unconformity is visible in the opposite wall of the canyon near the left. Taking it in are Mike, Sarah, Marietta, Kelly, Diana, Christian, and Karen.