The tiling image in the masthead of the dam spillway gates was taken from the image below on the
US Army Corps of Engineers website at:
http://www.sas.usace.army.mil/lakes/thurmond/timeline.htm
It shows the dam's spillway gates open in 1998. The tiling image uses
parts of three gates,
but is stretched 50% wider than normal. The tile used also edited to hide the tile edges.
Look how in the real picture that, from the left side to the right side, the perspective
of the walkway on the concrete gate buttress changes substantially against the
metal dam gate. On the tiled image in the
masthead, that doesn't
happen!!

The tile
On another image at the Corps of Engineers site you can count that the dam actually has 23 gates. On my 1600 pixel wide monitor I can see parts of 22. Close...
