This is an impressive cumulonimbus anvil cloud looming over the Seven Sisters Mountain Range in the Black Hills of South Dakota. It was captured shortly after sunset — the view is looking toward the southeast. Photographer: David A Brown
The anvil towers over 50,000 ft (15,240 m) and so is fully illuminated by the Sun, though, the surface is by now quite dark. This storm was one of many that gave the Black Hills a very wet spring in 2011 and also contributed to record flooding along the Missouri River. A gibbous Moon is seen rising above the massive storm clouds. Photo taken on June 9, 2011.