After visiting Bob in Sacramento, I flew back home over the Grand Canyon, and took the top photo of the desert about 50 miles ENE of Flagstaff. The perfectly straight line in the winter landscape has nothing to do with the aircraft window, but tracked from right to left as we passed over it. There's less snow on the right side of the line; perhaps there is a temperature difference in the ground. I brought up Google Earth to see a satellite view of the same area, and the line is there also, as you can see in the bottom Google Earth photo. It runs absolutely straight for 50 to 70 miles. Any Geologists around that can supply an answer for this?