Nevada

Hoover Dam, a concrete arch-gravity dam in the Black Canyon of the Colorado River on the border between the US states of Arizona and Nevada. Hoover Dam ,finished in 1936, impounds Lake Mead, the largest reservoir in the United States by volume. The dam's generators provide power for public and private utilities in Nevada, Arizona, and California. Hoover Dam is a major tourist attraction; nearly a million people tour the dam each year.

Joe Klamar/AFP

The sun rises over the Hoover Dam, a concrete arch-gravity dam in the Black Canyon of the Colorado River on the border between the US states of Arizona and Nevada. The Hoover Dam was finished in 1936 and impounds Lake Mead, the largest reservoir in theUS by volume.

Lightning strikes above the Mandalay Bay and Luxor casinos on the Las Vegas Strip as a thunderstorm moves through Las Vegas...Lightning strikes above the Mandalay Bay (L) and Luxor (C) casinos on the Las Vegas Strip as a thunderstorm moves through Las Vegas, Nevada July 20, 2013. REUTERS/Steve Marcus (UNITED STATES - Tags: ENVIRONMENT CITYSCAPE TPX IMAGES OF THE DAY)

Steve Marcus/Reuters

Lightning strikes above the Mandalay Bay and Luxor casinos on the Las Vegas Strip as a thunderstorm moves through Las Vegas, Nevada in the US. Read more