The first Nevada test, Operation Ranger, occurred in January 1951 - a 1-kiloton device that proved the desert could serve as a domestic proving ground. Tests escalated rapidly: larger weapons, more complex designs, atmospheric detonations that sent mushroom clouds miles high. Soldiers were exposed deliberately to study radiation effects. Test animals - pigs, dogs, sheep - were placed at varying distances to measure blast and radiation casualties. Houses were built and destroyed repeatedly. The tests peaked in the 1950s and early 1960s; the Limited Test Ban Treaty of 1963 forced tests underground, where they continued until 1992.

Underground tests created a landscape of subsidence craters - circular depressions where the ground collapsed into cavities left by vaporized rock. Sedan Crater, 1,280 feet wide and 320 feet deep, was created by a 104-kiloton device in 1962 as part of a program exploring 'peaceful' nuclear explosions. The crater is visible from space. Hundreds of smaller craters dot the site, marking test locations. The landscape looks lunar, which is appropriate - astronauts trained here for moon landings. The craters are permanent monuments to the weapons tested beneath them.

The Nevada Test Site is one of the most contaminated places on Earth. Atmospheric tests spread fallout across the southwestern United States and beyond; downwind communities experienced elevated cancer rates that took decades to acknowledge. Underground tests contained most radioactive material, but plutonium and other contaminants remain in the soil. Some areas will be hazardous for 10,000+ years. Cleanup is ongoing but incomplete - the contamination is too extensive and too dangerous to fully remediate. Workers still operate at the site, managing waste and monitoring conditions under strict safety protocols.

The Nevada National Security Site (its current name) offers public tours several times monthly. Buses carry visitors through the site, stopping at the Sedan Crater, atmospheric test locations, and remnant structures. The National Atomic Testing Museum in Las Vegas provides context and exhibits. The tours book months in advance; security clearances are required. Visitors cannot leave the bus at most stops; photography restrictions apply. The experience is surreal: standing where nuclear weapons detonated, trying to comprehend the scale of what was tested here, posed against a backdrop that looks like science fiction become fact.

Tours of the Nevada National Security Site depart from the National Atomic Testing Museum in Las Vegas. Tours operate monthly and require advance registration (months in advance for popular dates). U.S. citizenship or legal residency required; foreign nationals may request approval with advance notice. The tour is a full day (6-8 hours) and includes bus transportation, security screening, and guided stops at significant locations. The Atomic Testing Museum is worth visiting regardless - exhibits cover the Cold War, nuclear physics, and the human impact of testing. The museum is on Flamingo Road, east of the Strip. Las Vegas has extensive services. Bring government-issued ID; leave cameras and phones on the bus where required.