Trinity Site Tour


Trinity Site Marker - Eric Russell Photo

Trinity Site Monument

The popular, interesting Trinity Site Tour begins and ends in San Antonio, 10 miles south of Socorro. The Trinity Site is the site of the first detonation of an atomic bomb in 1945. The scenery is wonderful, since the area has not been grazed since 1945. The tour is quite flat but there may be winds since it is wide open. There are great views of the low Oscura Mountains to the east. The Little Burro Mountains are visible to the southeast of the route and the Mockingbird Mountains are south. Interestingly, the southern-most road is the northern perimeter of the White Sands Missile Range Century that starts and ends in Tularosa.

There is no public vehicular traffic after entering the Stallion gate which is a real treat. Since we ride on the weekend there is very little worker vehicle traffic. Spring or fall is the best time for this ride since it is very hot in the summer.

From San Antonio ride east about 12 miles on US380 to the Stallion Range turnoff. Then ride south about 5 miles to the Stallion Range entrance. At the entrance you can pickup pamphlets if you don't have one. Then ride south about 13 miles south. Turn left (east) at the Permanent High Explosive Testing Site (there are signs) and ride the final 4 miles. Soon after the turn the circular Trinity Site area can be seen in the distance.

A side trip to the McDonald ranch, where the first bomb was assembled, is sometimes allowed on the way south. This is about a mile off the pavement on a packed gravel road rideable by road bikes and tandems.

There is no food or water or other services along the route, so come prepared. The range is normally closed so this ride must be arranged with the White Sands Missile Range personnel. You must carry picture id on you while on the range. Port-a-johns are available a the gate and at the Trinity site. Riders must not leave the road due to the presence of unexploded ordnance. Photographs may be taken at the Trinity Site but not anywhere else along the route.

Have a green-chili cheeseburger at the original Owl Cafe in San Antonio after the ride.
The WSMR is normally closed to the public. The NMTS is sometimes able to offer this tour once a year with the cooperation of the White Sands Missile Range. Watch the bulletin for a fall / winter ride. Don't ride out there on your own expecting to get in - you won't.
Distance: 68 Miles / 1,600' elevation round-trip, and a 34 mile / 800' elevation gain round-trip option. Pretty flat but it can be windy.

Getting There: This description starts and ends in San Antonio. Take I-25 south from Socorro 10 miles to US380, exit 139 and turn east, driving less than a mile to San Antonio. A 34 mile / 800' option is possible by parking outside the Stallion Range entrance, east of San Antonio.

Roadway: The roads to the Trinity Site in the missile range are paved, two lanes with almost no traffic since it not open to public vehicular traffic during bike rides. US380 is pretty flat, 2-lanes, with light traffic. The side trip to the McDonald ranch, if allowed, is about 1 mile of packed gravel road each way that is easily rideable by road bikes or tandems.



Trinity Site Cuesheet

PDF Version of the cuesheet below. Click on the link, then use the File/Print menu command to print the file.

Trinity Site CueSheet / 68 Miles Round-trip, 1,600' Elevation gain
Mileage Waypoint Leg Description


San Antonio Start location - try the park across from the Owl Cafe.


Turn off to WSMR White Sands Missile Range Stallion Site turnoff.


WSMR Entrance Photo Id Required. There is a parking lot with port-a-potties just outside the guard shack.


Explosives Test Site HQ The turn is marked, you can't see the site yet.


Trinity Site The circular Trinity Site is visible in the distance after the turn. Stop at the dirt parking lot. There may be porta-potties here. There are several exhibits and signs. Those are the Oscura Mountains to the east.
Return by the same route or take the McDonald Ranch option if it is allowed. Wave at the guard on the way out of the WSMR. Turn LEFT (west) on US380 to San Antonio. There's only the one hill on US380. Hopefully, there is not the usual afternoon west wind on US380.


San Antonio Check out the historic Owl Cafe bar.


  The Historic McDonald Ranch Tour option, only when allowed, starts at the Trinity Site.


Trinity Site Starting at the Trinity Site, ride south from the parking lot about a mile and a half paralleling the Oscura Mountains to the east.


Turn off to Ranch Signed. Turn left (east) onto packed dirt/gravel road. Easy ride on road bikes and even tandems. Tour the historic headquarters / ranch house. Oscura Peak (8,638') directly east of the ranch, maybe 5 miles away, is also on WSMR. Return by the same route to the pavement. 


Back to the pavement Turn left (south) if this is the allowed direction. You might have to backtrack to the Trinity Site.


Intersection Turn right (north) and head back towards the way you came. There isn't much else out here. The Little Burro Mountains are southeast of the turn and the Mockingbird Mountains are south.
Interestingly, further southeast from the intersection this road is the northern perimeter of the WSMR Century out of Tularosa.


Explosives Test Site HQ Continue straight (north) through the intersection.


WSMR Entrance Continue straight through. Wave a thank-you.


US380 Turn left (west) towards San Antonio. Just the one hill now.


San Antonio Starting location. Have lunch and thank the WSMR folks for a great ride.

Trinity Site Access Map

Once on White Sands Missile Range the route is the main paved road. Most of the other roads shown on the maps on WSMR below are dirt roads.

Trinity Site Access Map

White Sands Missile Range Route Map

The route continues at the point the map above leaves off. Note that the tour does not always go to the historic McDonald Ranch house. The route is pretty definite since the route follows the major paved roads and most of the other roads shown are dirt roads. These two maps have the same scale.

Trinity Site Map

Trinity Site Elevation Profile

Out and back elevation profile from San Antonio to the Trinity Site. Note that there is only a elevation range of about 500' and a total elevation gain of about 1,600' over the 73 miles so don't be scared by the impressive profile.

Elevation Profile