can you visit trinity site new mexico

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Trinity site.

US DEPARTMENT OF ENERGY

Trinity Site is located on White Sands Missile Range and is closed to the public. Twice a year, the US Army hosts a Trinity Site Open House when the public may visit Trinity Site. 

On July 16, 1945, the atomic age began. Manhattan Project scientists detonated the first atomic device, known as “the Gadget,” at 5:29 am Mountain War Time at the Trinity Site in the Jornada del Muerto desert of New Mexico.  

For the Project Trinity test, the bomb was placed atop a 100-foot (30.48 m) tall steel tower that was designated Zero. Ground Zero was at the foot of the tower. Equipment, instruments, and observation points were established at varying distances from Ground Zero. The wooden observation shelters were protected by concrete and earthen barricades, and the nearest observation point was 5.7 miles (9.17 km) from Ground Zero. 

An incredible flash of light illuminated the sky as air temperatures rose to over 9,000oF (4982oC). Within seconds, witnesses saw the first mushroom cloud ever created by atomic weaponry. To most observers—watching through dark glasses—the brilliance of the light from the explosion overshadowed the shock wave and sound that arrived some seconds later. A multi-colored cloud surged 38,000 feet (11.58 km) into the air within seven minutes. Where the tower once stood was a crater one-half mile (804 m) across and 8 feet (2.43 m) deep. Sand in the crater was fused by the intense heat into a glass-like solid, the color of green jade. This material was given the name trinitite. The explosion point was named Trinity Site. 

Although no information on the test was released until after the atomic bombings of Japan on August 6 and 9, 1945, the flash of light and shock wave made a vivid impression over an area with a radius of at least 160 miles (257.49 km). Kenneth Bainbridge, director of the Trinity Test, called it “a foul and awesome display.” Despite months of speculation and wondering over what would happen, “the atom bomb did not fit into any pre-conceptions possessed by anybody,” according to future Los Alamos National Lab director Norris Bradbury. After three years of directing the project’s scientists and much anxious chain smoking at the Trinity Site, Robert Oppenheimer simply said to his brother, “it worked.”    

After the explosion, Trinity Site was encircled with more than a mile (1.6 km) of chain-link fencing. Signs were posted to warn people of radioactivity. By 1953, much of the radioactivity had subsided, and the first Trinity Site open house was held in September of that year. 

In 1965, Army officials erected a monument on Ground Zero. In 1975, the National Park Service designated Trinity Site as a National Historic Landmark. The landmark includes base camp, where the scientists and support group lived; the McDonald ranch house, where the plutonium core was assembled; as well as Ground Zero. 

Continue Your Journey 

K-Site, Q-Site, and L-Site were critical locations for studying and understanding implosion before the Trinity Test. Learn more about the history of the Manhattan by visiting the Bradbury Science Museum ! The museum’s interactive exhibits share stories from the project and provide a glimpse of other “behind the fence” historical sites. 

Manhattan Project National Historical Park

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Last updated: March 17, 2023

Trinity Site Offers a Rare Chance to Visit Ground Zero of the World’s First Atomic Bomb Explosion

The detonation site is only open to civilians twice a year

Jennifer Nalewicki

Travel Correspondent

July 16, 1945 was a day that changed the world forever. At 5:29 a.m. Mountain War Time, just minutes before sunrise, the night sky above central New Mexico was illuminated in a brilliant fireball of white light as the U.S. military tested the world’s first atomic bomb . Called Trinity Site and located on the grounds of the White Sands Missile Range about 70 miles west of Alamogordo, the site is typically off limits to civilians—but on October 7, visitors can experience it firsthand during its biannual open house.

Held on the first Saturday of every April and October, the open house is the only opportunity the public has to access the missile range, which normally serves as an active site for the U.S. Army to test out new weaponry. During the open house, visitors can see ground zero, where the plutonium-based A-bomb was detonated more than 70 years ago as part of the Manhattan Project . The open house also includes a visit to the McDonald Ranch House, a 1913 adobe home built by Frank Schmidt, a German immigrant, and where the device’s plutonium core was assembled.

Today, a monolith marks ground zero along with what’s left of the footing of a 100-foot tower that military personnel used during the detonation. Also on view: photos taken during the explosion, and the leftover bomb casing from “ Fat Man .”

“Most of the tower was vaporized during the explosion,” Drew Hamilton, a public information and community relations specialist for White Sands Missile Range, tells Smithsonian.com. “Since the explosion, much of the surrounding area has more or less returned to the way it would naturally be. There are no bushes growing around ground zero, but it’s because we regularly mow it. If we didn’t, it would look like the rest of the landscape.”

Visitors may also come across crumb-size pieces of Trinitite, a rock-like byproduct leftover from the explosion known for its glassy texture and deep green hue. (Since White Sands is a national monument, however, visitors are prohibited from removing anything from the site.)

And while Trinity Site has been cleaned up since the atom bomb detonation, its  radiation levels  remain above that of naturally occurring background levels. To put this into perspective, Hamilton gives the following example:

“Radiation is everywhere, it’s a naturally occurring phenomenon,” he says. “But it’s a little bit higher [at Trinity Site as compared to] the surrounding territory. During a one-hour visit, you’ll be exposed to approximately half a millirem of radiation. In comparison, during a flight aboard a commercial airliner from New York City to Los Angeles, you’ll be exposed to 2 millirems. You’ll get the same exposure from the Trinity Site as you would if you ate eight bananas, which, because of their potassium content, are naturally radioactive.”

This year’s Trinity Site open house will take place from 8 a.m. to 2 p.m. on October 7. Admission is free and reservations are not required. Pets are allowed and must be leashed. To reach Trinity Site, take exit 139 off Interstate 25 to State Highway 380 and drive east 12 miles to Stallion Gate. Make sure to bring a valid ID to show at security checkpoints. Drivers should be prepared to provide proof of insurance. 

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Jennifer Nalewicki | | READ MORE

Jennifer Nalewicki is a Brooklyn-based journalist. Her articles have been published in The New York Times , Scientific American , Popular Mechanics , United Hemispheres and more. You can find more of her work at her website .

White Sands Missile Range Museum

Atomic. Missile. Space. Birthplace of American Ages.

Trinity Site

Trinity Site Open House

The 51,500-acre area was declared a national historic landmark in 1975. The landmark includes Base Camp, where the scientists and support group lived; Ground Zero, where the bomb was placed for the explosion; and the Schmidt/McDonald Ranch House, where the plutonium core to the bomb was assembled. Visitors to a Trinity Site Open House are given the opportunity to visit Jumbo, Ground Zero, and the Ranch House. In addition, one of the old instrumentation bunkers is visible beside the road just west of Ground Zero.

This marker shows the location of Stallion Range Gate, the general public entrance to Trinity Site off of Highway 380.

Alamogordo, New Mexico True

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Trinity site.

www.wsmr.army.mil/Trinity

The world was forever changed on July 16 th, 1945 at the Trinity Test Site. It was here at the White Sands Missile Range that the first atomic bomb was detonated and brought a quick end to the Second World War in the Pacific. Today it is a national historical site that is open to visitors just 2 days per year, (pending Army approval) in April and October.  Visitors can see ground zero, the ranch house where the bomb was assembled, and one of the instruments bunkers. For more information about visiting the site go to www.wsmr.army.mil/Trinity

History of Trinity Site www.nps.gov/whsa/learn/historyculture/trinity-site.html

You have a few different options when it comes to visiting Trinity Site.  You can enter through the Stallion Gate which is off of Hwy 380 between Carrizozo and San Antonio, NM at the times specified on the White Sands Missile Range website.  You can also caravan into the site, this route takes you from Tularosa, NM through the Missile Range with other travelers. To participate in the caravan you need to meet in the Athletics parking lot on the west side of the Tularosa High School off of La Luz Ave.  Line up starts at 7 am and the caravan will leave promptly at 8 am.  Please arrive no later than 7:45 am so that officers will have a chance to check your license and registration, and give you a pass to place in your window signifying that you are a part of the caravan.  You may return to Tularosa with the caravan between 12:30 and 1 pm, or leave on your own through the Stallion Gate.  Please ensure that you have a full tank of gas and bring plenty of water with you.  Finally, the International Space Hall of Fame Foundation (New Mexico Museum of Space History support group) hosts a guided tour to the site in charter buses, they also provide b a sack lunch, water, and a guide tour of the museum upon return.

Find more info and register for the guided tour at http://nmspacetrail.com/sites/NMMSH/Trinity-Site-Tour/register.html For more information about the caravan lineup https://www.alamogordo.com/trinity-site / New weekend itinerary coming soon!

NEW!!! The Tularosa Basin Museum of History is hosting a viewing followed by a Q&A, of the new documentary, 'Alamogordo, Center of the World, Trinity 1945' the Friday evening before each open house.  Tickets are available through the museum at the corner of White Sands Blvd & 10th, 575-434-4438.  The film will be shown at the historic Flickinger Center for Performing Arts (1110 New York Ave. Alamogordo, NM) in downtown Alamogordo. For more info call 575-437-2202.

Directions to Trinity Site: http://www.wsmr.army.mil/Trinity/Pages/DirectionsMaps.aspx

More information about the caravan to Trinity Site visit www.alamogordo.com

Map to caravan lineup site, limited to 125 vehicles.

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