St. Thomas, Nevada
St. Thomas was originally a Mormon settlement that was "abandoned" twice. First in 1871 when the Nevada state line was shifted one degree of longitude to the East and second after the construction of the Hoover Dam which created Lake Mead. Recent drought years have exposed the building footprints and have allowed for exploration and examination of the site.
In March 2009, I visited St. Thomas, Nevada to explore the site and captured GPS traces, gigapixel panoramas, and a photosynth of one of the old homesteads. Most buildings had the remnants of wells in the back and at this particular site there were bits of glass, metal, etc. At high water level the site is submerged by Lake Mead.
The Special Collections Library at the University of Nevada, Las Vegas has a few photos that were taken by the Bureau of Reclamation. See Historic photographs of St. Thomas