Eventually, the mountains give way to the Glenn Canyon, a vast crack into which we descend, past sheer cliffs that have been ripped upward and angled by some ancient event. We pick up the Colorado River and cross over it many times as it lazily zig-zags through these canyons, while the highway, elevated and flat, moves on a more direct course. The crack in the earth widens, making room the railroads – we see a passenger train, and freight trains along the way – and into valleys with forested slopes to the south and parched rocky slopes to the north.
Eventually, these mountains are left behind, and a broad valley opens up below, the green of fields contrasting with the rocky sentinels that spread away from its center. Soon enough we enter Grand Junction, Colorado, and make for the Colorado National Monument.