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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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Trinity site, nm.
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: August 23, 2024
UponArriving
Trinity Site Open House Guide (New Mexico)
Over the years of turning out content for this blog, I’ve visited a lot of historical sites but I’ve never visited a site quite like the Trinity Site in New Mexico.
It’s an ultra-remote site barely ever open to the public and it’s home to one of the most pivotal moments in mankind’s history.
If you have any type of interest in the atomic era, this is a bucket-list worthy destination for sure.
In this article, I’ll tell you everything you need to know about visiting the Trinity Site’s open house.
Table of Contents
What is the Trinity Site?
The Trinity Site is where the first nuclear bomb exploded on July 16, 1945 at 5:29 AM mountain war time. Two days out of the year there is an open house that allows the public to visit the site along with other related sites like the McDonald Ranch House.
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How to visit the Trinity Site
It is free to visit the Trinity Site but you can only visit the site two days out of the yea r, which is usually the first Saturday of April and October. However, sometimes they do change the dates around a little bit.
There are three main ways that you can visit the Trinity Site.
Alamogordo Caravan
One way to experience the Trinity Site is to take part in the Alamogordo Caravan.
Line up for the caravan begins at 7:00am at the Tularosa High School Athletic Field parking lot and the tour will enter the missile range through the Tularosa Gate at 8:00am and arrive at Trinity Site around 10am.
It is only open to the first 125 vehicles that show up.
The journey is 85 miles one-way to Trinity Site.
Stallion Gate
The other way to experience the Trinity Site (which is the way that we did it) is to simply arrive at the Stallion Gate. This gate is located on the north side of the missile range on U.S. highway 380, 12 miles east of San Antonio, NM.
The Stallion Gate Hours are from 8:00 a.m. to 2:00 p.m. and the Trinity Site closes promptly at 3:30 p.m
Once you show up at the military testing site, you’re not allowed to take any photos until you arrive inside the Trinity site so keep that in mind.
It’s about a 30 minute drive from the Stallion Gate to the parking lot for the Trinity Site.
At the Stallion Gate, you’ll go through a security checkpoint where every passenger 18 years and older will need to show an ID and declare that they are not bringing in weapons or any illegal items. (It only takes a few seconds to get through.)
Once you arrive at the parking area, military personnel will direct you to your specific parking spot.
Related: New Mexico Safety Corridors Explained
Book a tour
You can also book a tour to get you there.
For example, the New Mexico Museum of Space History offers a package deal where you can get a bus ride to and from the site, some snacks, and access to the museum.
We checked out the museum and thought that it was a pretty well done space museum. They also have a small exhibit on Trinitite which was cool to see.
Where to stay
You might consider staying in Albuquerque, New Mexico, or in Alamogordo which is where we stayed because we decided to explore the New Mexico Museum of Space History and White Sands National Park the next day.
If you’re headed to Albuquerque, be sure to check out The National Museum of Nuclear Science & History and consider adding Los Alamos as an additional stop.
Los Alamos was the headquarters for the Manhattan Project and they still have a couple of museums you can check out like the Los Alamos History Museum and the Bradbury Science Museum .
Trinity Site history
To fully grasp and appreciate the history of the Trinity Site it helps to understand how it fits into the overall efforts of creating the atomic bomb.
The history of the atomic bomb begins in Berlin, Germany when in 1938, scientists discovered how to split the nucleus of the uranium atom (fission).
This discovery came close to the beginning of World War II when Adolf Hitler invaded Poland in September 1939.
The breakthrough in fission created serious worry that the Nazis would get their hands on a nuclear weapon which would obviously not be ideal to say the least.
Concerned Hungarian physicists helped write a letter to President Roosevelt (FDR), signed by none other than Albert Einstein, to warn the US about the prospect of an “extremely powerful” Nazi atomic bomb.
After that, it didn’t take long for FDR to authorize a top-secret project to begin researching the atomic bomb.
The initiative went through a few name changes but ended up as the: Office of Scientific Research and Development (OSRD).
Things took off after the bombing of Pearl Harbor on December 7, 1941 when the US found itself involved in World War II with a formal declaration of war on both Japan and Germany.
President Roosevelt authorized the Manhattan Project on December 28, 1942 and on the 18th floor of 270 Broadway in New York City, the Manhattan Project began.
General Leslie Groves was appointed to lead the Manhattan Project after just just finishing the completion of the Pentagon.
Groves went on to recruit Robert Oppenheimer, an instructor at the University of California at Berkeley and a bit of an odd selection given his lack of managerial experience and associations to communism via family members.
But he proved to be an ideal candidate and an excellent recruiter of scientific talent.
The Manhattan project sought to create atomic bombs from two substances: uranium and plutonium.
For uranium, they were focused on acquiring U-235 and they built a huge complex and town in Oak Ridge, Tennessee to accommodate 30,000 workers .
For Plutonium, the Hanford Engineer Works produced plutonium at a site along the Columbia River in Washington state.
They also needed a place to develop and test the bombs.
They wanted somewhere secret and remote but still appealing enough to attract renowned scientists all over the world so they went with Los Alamos, New Mexico.
On January 1, 1943, the Los Alamos Laboratory — known as Project Y — was formally established .
And a few months later , the University of California signed a contract with the United States Army Corps of Engineers to operate the secret laboratory.
They once again built an entire city just for the purpose of the Manhattan Project and hundreds of people would arrive to the city with no clear idea as to what they were actually building.
(Pretty much only scientific personnel had an idea of what they were doing.)
Questions were highly discouraged and on paper the city didn’t actually exist.
Many experiments were done as the teams collaborated to construct the bombs and waiting for the nuclear material to arrive. At some point, though, it became clear that the plutonium bomb was going to be an issue.
The issue was that creating an explosion with plutonium was a much more complicated process.
The scientist had to create an entirely different type of mechanism to initiate the chain reaction and that’s when they came up with implosion.
The implosion-type nuclear weapon , “held a core of subcritical plutonium which would reach criticality when high explosives surrounding the core detonated causing the core to compress instantly.”
The creation of this new type of work and was so challenging that it required bringing in a lot more scientists. Unfortunately, when bringing in more talent at least one Russian spy made his way into the team.
The team would ultimately make progress but unexpected challenges arose in April 1945 and the work was interrupted when FDR died in office.
Shockingly, the Vice President Harry Truman did not even know about the Manhattan Project when he took office!
A month later, on May 7, 1945, Germany would surrender but the war was still going strong in the Pacific Theater and an atomic weapon was being considered for use against the Empire of Japan.
The allies had battered the Empire of Japan’s military down to a shadow of what it had been before but casualties were still running very high.
But before any bombs would be dropped, some testing needed to be done.
Testing at the Trinity Site
Back in September 1944, around the time nuclear material was arriving, New Mexico’s Alamogordo Bombing and Gunnery Range (aka the Trinity Site) had been selected as the the test location .
It was located about 210 miles south of Los Alamos, and in November 1944 construction of the base camp began.
All of the components of the uranium atomic bomb had been tested giving scientists the mathematical certainty they needed to know that the bomb would work.
But because the plutonium bomb was more complex they needed a test run to ensure that it would work.
The plutonium bomb set to be tested at the Trinity Site was known as “Gadget.”
The core of the bomb consisted of a grapefruit-sized ball of plutonium and was delivered to the McDonald Ranch House on July 11, 1945 and the bomb was assembled on July 13, 1945.
The bomb, a large 6-foot sphere covered with wires and patched up with tape, was then hoisted up a 100-foot steel tower for the test.
At the time, none of the scientists truly knew what was going to happen. In fact, many thought the bomb would be a dud.
On the day of the test, the weather did not cooperate at first and the team postponed the test until the skies cleared up a little bit.
Then at 5:29:45 a.m. Mountain War Time on July 16, 1945, first atomic bomb was tested .
After the bomb exploded, clouds of bright reds and purples filled the sky up to 40,000 feet high. People said they felt the warmth of the sun.
Local newspapers were told that an ammunition depot had exploded which had resulted in the spectacular display but those at the site knew the truth: humankind had entered the atomic age.
The Trinity site
Ground zero.
Ground Zero is about a quarter mile away from the parking lot so you have to walk a little bit to get there.
Once you arrive, you’ll see a monument towering in the middle.
Erected in 1965, The Trinity Monument is a lava-rock obelisk about 12 feet (3.7 m) high that marks the explosion’s hypocenter.
Crowds gather around the monument pretty quickly so you might need to exercise some patience to get a photo.
Right next to the obelisk, you can find the remains of the 100 foot steel tower that hoisted Gadget.
Along the perimeter of Ground Zero, you’ll find photos hanging from the fence that will give you some insight into everything going on at the time of the test. It’s best to start from right to left when viewing these.
There’s a structure that covers some of the original soil from the test but sand and dust got in and covered up the original soil so the viewing window has been closed.
There’s also a bomb casing that I believe was going to be used for future atomic bombs. It’s almost identical to the casing used for the fat man bomb which was dropped on Nagasaki.
Trinitite is a radioactive green glass-like substance that covered the depressed area where the explosion took place after the test.
There’s different explanations as to how the trinitite was formed.
The simple and long-held explanation is that the heat simply heated the sand until it became glass.
One hypothesis is that the explosion brought pieces of sand and rock into the fireball and liquefied the pieces which eventually fell down like rain into the crater and hardened.
I’m not sure which explanation might be more accurate but I think it’s safe to say that it had a lot to do with the heat from the explosion.
Most of the trinity it is light green but other pieces are slightly different colors. Some are black and others look slightly red and that’s because those contain elements that were vaporized during the test.
For example, the black pieces contain elements from the steel tower and the red pieces contain elements from the copper in the wires.
If you stroll around Ground Zero and look closely at the ground it won’t be very difficult to find pieces of trinitite.
They possess background levels of radiation and you are okay to touch them but probably not a good idea to do something stupid with them like swallow them. It’s also a federal crime to remove them from the property.
You’ll also want to stop by the trinitite fueling station. Here, you can get a close look at trinitite and also use a geiger counter to detect the radiation levels of the trinitite.
McDonald Ranch House
The McDonald Ranch House is where they assembled the bomb on July 13, 1945. Built in 1913 by Franz Schmidt, a German immigrant and acquired by the McDonald family in the 1930s, the ranch was eventually taken over by the government in 1942.
In order to get there, you need to head to the bus stop which is located right by the parking lot. It’s only about a 5 to 10 minute bus ride to get to the ranch house. Keep in mind that dogs are not allowed on the bus unless they are service animals.
When you arrive, you can simply wander through the McDonald Ranch House at your own pace. There should be somebody inside that can help answer any questions you might have and who can show you around.
They also had a table with photographs set out in front so you can learn a little bit more about the structure.
The northeast room was designated the assembly room where they had work benches and tables.
To keep all of the sand and dust from ruining the instruments, they covered the windows and walls with plastic. In fact, you can still see some of the nails that were used to seal up the windows.
As mentioned above, the plutonium core was delivered to the ranch house on July 11, 1945 and it was assembled on July 13, 1945.
The explosion occurred only 2 miles (3.2 km) away and it blew most of the home’s windows out but did not significantly damage the structure.
Instead, it was the years of rain water leaking through the roof that was responsible for the deterioration.
In 1984 it was restored by the National Park Service to appear as it did on July 12, 1945
Near the main parking lot you’ll see Jumbo which is a large structure which was once the heaviest object to ever be transported by rail.
The 25-foot jumbo container was initially going to be used to contain the plutonium with its 14 inch thick walls in the event of a botched explosion.
However, after they realized that they would have plenty of plutonium for additional bombs they didn’t need to use jumbo for the explosion.
So they hoisted it from a tower about 800 yards away from ground zero and while that tower would be vaporized during the explosion, jumbo would remain intact.
While they did not use it for this explosion, it was used on April 16, 1946, when an Army ordnance team detonated eight 500 lb bombs in the bottom of the steel container.
Food and souvenirs
You’ll also be able to find food and souvenirs at the Trinity site.
Souvenirs range from about $3 to $20 and they have a lot of the typical stuff like magnets, stickers, patches, and T-shirts.
As for food, they’ll have breakfast burritos, hamburgers, hotdogs, and some other snacks. I believe the registers should take credit cards but I would bring cash just in case.
Also, they do have bathrooms which are a little bit of a walk from the parking lot.
Visiting the Trinity Site is not very easy because it is only open two days out of the year and it’s basically in the middle of nowhere.
But it is still absolutely worth planning out a visit because it’s hard to find a location that compares to the Trinity Site in terms of its importance to the history of mankind.
Daniel Gillaspia is the Founder of UponArriving.com and the credit card app, WalletFlo . He is a former attorney turned travel expert covering destinations along with TSA, airline, and hotel policies. Since 2014, his content has been featured in publications such as National Geographic, Smithsonian Magazine, and CNBC. Read my bio .
very informative. i am planning a visit in october 2023. was wondering about the mcdonald ranch house, and you answered all my questions…. this trip in october will knock off another event on my bucket list.
July 2023: The tour package is now $150 per person.
Confused. Sorry. From a that I see it’s free to drive and take pictures of the monument and see site from distance What is the 150.00 Charge for. It’s free to drive up and see site frown distance Can I also see McDonald house for free. Please advise. Coming from Dallas How can I get free brochures for trinity mailed to me on trinity testing Came I get a number to call. Please let me know.
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