On my return flight from the ATF conference in San Francisco I spotted two interesting views out of my airplane window (facing South).
The first was an interesting landform in Wyoming:
A strip of dunes mostly in the Great Divide Basin built from sand blowing through a gap in mountains to the West. This picture covers about 90km (55 miles) in the East-West direction. (Thumbnail from Google Maps; click to go there)
The Killpecker Sand Dunes are formed from an old riverbed which provides a source of sand, with the prevailing westerly winds blowing this sand though a gap in the mountains across the plain.
The blown sand forms this long cigar-shaped dark area with patchy dunes in it. I expect that the dark shape is from the sand wearing away lighter-coloured surface materials. This erosion probably forms a bit of a depressed area which keeps the sand confined despite minor variations in the wind direction.
The other interesting sight was a thunderstorm near the Wisconsin/Illinois border, west of Beloit. This was just after dusk so the lightning flashes were easily seen, though the bolts themselves were mostly hidden within the cloud. Although it was not a huge storm, the view was excellent so I took a short movie of in using my cell phone.
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