After about a year and a half, David Klinger finally identified this dam which appears on the back of a $20 Military Payment Certificate (MPC). The question was, where was the dam? The dam had been erroeneously identified as "Hoover Dam," but as you can see, this is most definitely not that famous structure.

 
Click on the image to see a large version.

What it looks like on the "MPC."

After a substantial number of search attempts, Mr. Klinger discovered from Larry Stephens, the Executive Director of the United States Society on Dams, that the vignette represents the Theodore Roosevelt Dam on the Salt River near Globe, AZ. It was built by the Bureau of Reclamation and completed in 1911.

The Roosevelt Dam. was started in 1903. Mr. Klinger writes, "It was a masonry dam, or as the engineers call it a "rubble-masonry, arch-gravity dam". This just means that it was made of dolomite blocks, rather then poured concrete. It's unique cyclopean-masonry, thick arch designed earned it a listing on the National Registry of Historic Places. The original name of the dam was simply Salt River Dam #1. When it was dedicated in 1911 Teddy Roosevelt was there and gave the keynote speech. I have several pictures of that. The name wasn't changed to Theodore Roosevelt Dam until 1959. By the way, it is only about 75 miles N-E of Phoenix."

"Back to the dam. In 1911 this was the largest masonry dam in the world. In the 1980s the dam was renovated under the Safety of Dams program. The original masonry dam was encased in poured concrete and raised in height by 70'. That change wasn't completed until 1996. So the renovation took much longer than the original construction and cost much more! So what's new?"