Introduction – quoting from the article (on bookofresearch.com) below:
“On August 10, 1990, Bill Miller, a pilot in the Idaho Air National Guard, noticed a huge etching on a dried-up lake-bed while flying over it, in Oregon State in the United States. The massive formation was a quarter of a mile in width and was etched 3 inches deep into the surface. In his earlier round about 30 minutes before Miller first noticed the glyph, there had been no trace of this formation. Neither had any of the other pilots of the Idaho National Guard (who regularly train over this corridor), observed any unusual activity or a design-in-process in this area. The etching simply appeared one morning. There was no possibility of any of the other pilots having missed such a prominent formation in process of being made.”
Image Credit: bookofresearch.com
To read further, please access the complete article below:
http://www.bookofresearch.com/unexplained-mystery-of-oregon-sri-yantra.htm