Trinity Site holds immense historical significance as the location where the first atomic bomb was tested on July 16, 1945, at 5:29:45 a.m. Mountain War Time. Spanning 51,500 acres, this site was designated as a National Historic Landmark in 1975. It encompasses base camp, ground zero, and the McDonald ranch house, where the plutonium core of the bomb was assembled.
During the Trinity Site Open House, visitors can explore various attractions. These include Ground Zero, the iconic “Jumbo” bomb casing, the McDonald House, one of the historic instrumentation bunkers, captivating historical photographs, a Fatman bomb casing, and a portion of the original crater created by the explosion, revealing a unique greenish glassy substance known as “Trinitite.” The intense heat and pressure of the atomic blast form Trinitite.
Trinity Site opens its gates to the public on the FIRST Saturday in April and the THIRD Saturday in October. Stallion Gate welcomes visitors from 8:00 a.m. to 2:00 p.m. It’s important to note that the Trinity Site closes promptly at 3:30 p.m. Admission to this event is free, and reservations are not required.
We invite you to visit our official website Trinity Site Open House:: White Sands Missile Range (army.mil) at for detailed information regarding tour entrance gates and times. You can find the latest updates and additional resources related to Trinity Site’s Open House events there.
Join us for a journey to Trinity Site, sponsored by the Alamogordo Center of Commerce. Only 125 cars will be allowed in the caravan. We recommend you arrive early as some cars start lining up as early as 6:00 AM. A food truck will sell delicious breakfast items and coffee to kickstart your day.
The meeting point for the caravan is at the Tularosa High School Athletic Field Parking lot. When you reach Tularosa, turn west off Hwy. 54/70 at Higuero St. Continue west until you reach La Luz Ave. Turn right on La Luz Ave. (heading north) until you reach the athletic field.
To ensure a smooth entry, please bring a government-issued photo ID for all individuals aged 18 and over. Also, please provide proof of insurance and registration for your vehicle or rental agreement. If you have a non-compliant state driver’s license, please look at the REAL ID information for acceptable alternative documentation.
The caravan will depart promptly at 8 a.m. It’s important to note that no latecomers will be allowed once the last person in the caravan has been identified. Visitors will travel together as a guided group to the Trinity Site, covering a total distance of 145 miles roundtrip. Please ensure your vehicle has a full gas tank, as no service station facilities are on the missile range. All visitors will exit Trinity Site on HWY 380.
While cameras are permitted at Trinity Site, they are strictly prohibited anywhere else on White Sands Missile Range.
Join us on this incredible journey and immerse yourself in the history and significance of the Trinity Site. Experience and learn about the pivotal moments that took place here. We look forward to seeing you on the Alamogordo Caravan!
Is there a fee?
No. There is no fee to visit the Trinity Site open house.
Are bathrooms available?
Yes. Porta potties are available at the site.
Do they sell food items?
Food items will only be sold from 8 a.m. to 12:20 p.m. Cash. Items range from $3-$5.
Do I have to register?
No, registration is not required.
Are there scheduled tours/ceremonies?
There are no scheduled tours or ceremonies. This is a self-guided open house event.
Can I take pictures?
Photos are allowed at Ground Zero and the McDonald ranch house. Photography is strictly prohibited on any other part of the installation.
What do I need to do to get on the installation?
A government-issued photo ID is required for everyone 18 years and over, and proof of insurance and registration for your vehicle or rental agreement. Please see REAL ID information for documentation to be used in place of or with a non-compliant state driver’s license.
Can I bring my firearm?
No weapons are allowed. There is no place to store weapons or firearms. Leave them at home.
Are pets allowed?
Pets are allowed if they are leashed, and their waste is picked up and put into a trash receptacle. Pets are not allowed on the shuttle that takes visitors to the ranch house.
Can I ride my motorcycle?
Yes, but you must wear a helmet and reflective gear.
What are the hours for the open house?
The Stallion Gate is open to the public from 8 a.m. to 2 p.m. The site closes promptly at 3:30 p.m.
How far will I have to walk?
The walk from the parking area to Ground Zero is about 1/8 of a mile.
What is there to see?
An obelisk at Ground Zero and the McDonald ranch house, which is where the plutonium core was assembled.
Can you accommodate large vehicles (RVs, Campers, Buses)?
Large vehicles such as recreational, campers, and buses are allowed at the open house. Ample parking is available for these types of vehicles.
Are there any handicapped restrooms?
Handicapped-accessible porta potties are available at the site.
Are there handicapped buses available to visit the McDonald Ranch House?
Unfortunately, there are no handicapped buses available to visit the McDonald Ranch House. However, architectural drawings and information about the ranch house are available near the entrance to ground zero.
Do you sell souvenirs/food?
Souvenirs and food are available for sale at the site. Cash only.
Is there a gas station nearby?
There is no gas station on the missile range. Trinity is in a very remote location, and please be sure you have a full gas tank. Depending on your destination, we recommend filling up your tank in Socorro, Carrizozo, or Truth or Consequences.
Is there wheelchair access?
Yes, the site is wheelchair accessible, about a 1/4 mile walk to Ground Zero from the parking area. We do not provide transportation. The 1/4 mile walk and area at GZ are not paved, and visitors must be prepared to travel through loose sand and rocks.
Do I have to register for the Alamogordo caravan?
No, you do not have to register to join the caravan. However, the caravan is limited to the first 125 vehicles. All others must enter the site through the Stallion Gate off U.S. Highway 380.
Where does the Alamogordo caravan meet?
The caravan meets at the Tularosa High School Athletic Field Parking Lot and leaves promptly at 8 a.m. A photo id will be required. The caravan is limited to the first 125 vehicles. All others must enter the site through the Stallion Gate off U.S. Highway 380. The caravan is one-way. Once at Trinity Site, you MUST exit through the Stallion Gate.
What time does the Alamogordo caravan leave from Trinity Site?
The caravan does NOT return to the Tularosa Football Field parking lot. Everyone in the caravan must exit through the Stallion Gate off U.S. Highway 380. See directions for more information.
Can I use my GPS device for directions to the site?
Because this is a remote location, do not rely on GPS for the location of Stallion Gate. GPS is not always an accurate tool to get to the site. Please follow the directions on the website or look at a traditional map.
Where is the nearest city with hotel accommodations?
The nearest city with hotel accommodations is Socorro, New Mexico. We recommend booking your hotel reservation several months in advance as hotels book up during open houses. Alamogordo, New Mexico, is also a great choice and is home to the newest National Park, White Sands National Park.
Is it harmful to visit Trinity due to radiation?
Radiation levels in the fenced, ground zero area are low. On average, the levels are only 10 times greater than the region´s natural background radiation. A one-hour visit to the inner fenced area will result in a whole-body exposure of one-half to one millirem.
Typical radiation exposures for Americans per the American Nuclear Society
- One hour at Trinity Site ground zero = one half mrem
- Radioactivity from air, water, and food = about 240 mrem per year
Is marijuana allowed on the installation?
Marijuana (in any form) is not allowed in this installation.