Because many of the rock formations appear to have been man made from a distance.
The Monument Valley is in Utah.
About 121 miles to Monument Valley, AZ.
Monument Valley is located in the Colorado Plateau Desert in the Four Corners region of the United States.
In Utah
Valley of the fallen
1933
NO
in southern utah close to arizona
Monument Valley.
Both Arizona and Utah.
That was Highway 163.
152 miles