In 1932, George Palmer was flying over the border between California and Arizona, near Blythe, and discovered the Intaglios... similar to, but 1000 years older, than the Nazca lines, these were made about 3000 years ago

After National Geographic published an article about the Blythe Intaglios in 1952, people began to visit the site which led to some destruction of the intaglios.

there are about 200 of them in the Colorado river area, and about 300 of the Nazca lines

https://en.wikipedia.org/wiki/Blythe_Intaglios