In 1932, pilot George Palmer spotted six giant figures etched in the ground along the Colorado River. Called intaglios or geoglyphs, these figures range from 95 feet to 171 feet in length: three humanoid, two animals, and one spiral. They were made by scraping away dark desert varnish to expose lighter soil underneath and may range in age from 1540 CE to 900 BCE. The figures share similarities with modern Quechan mythology, chiefly Mastamho, the creator.