The Grand Canyon is a steep-sided canyon carved by the Colorado River in Arizona, United States. It is mostly contained within the Grand Canyon National Park, one of the first national parks in the United States. It has a viewing platform shaped as a U. Jason Grace comes up with the idea that the canyon looks like some crazy god stuck their knife into the ground and dragged it across to give it its U form. It is very likely that this is how the canyon was formed.
The Grand Canyon is visited by Jason Grace, Piper McLean, and Leo Valdez on a Wilderness School field trip. While doing a worksheet on the viewing bridge, the three demigods and their protector Gleeson Hedge are attacked by Dylan, a Ventus in disguise by the sorceress Medea's orders. Leo is thrown off the bridge by Dylan and saved by Coach Hedge, who reveals he is a satyr with goat hooves that enable him to climb down the canyon wall easily. Meanwhile, Jason distracts the Venti, who have been summoned by Dylan, using Ivlivs. Piper is also thrown off the bridge and into the Canyon, but Jason saves her by jumping over the skywalk to save Piper, using his power to control the air currents. After Dylan escapes with Hedge, Annabeth Chase and Butch arrive and take them to Camp Half-Blood.