1.2 THE PROJECT TRINITY SITE

The TRINITY site was chosen by Manhattan Project scientists after
thorough study of eight different sites. The site selected was an
area measuring 29 by 39 kilometers* in the northwest corner of the
Alamogordo Bombing Range. The Alamogordo Bombing Range was located in
a desert in south-central New Mexico called the Jornada del Muerto
("Journey of Death"). Figure 1-1 shows the location of the bombing
range. The site was chosen for its remote location and good weather
and because it was already owned by the Government. MED obtained
permission to use the site from the Commanding General of the Second
Air Force (Army Air Forces) on 7 September 1944 (12). Figure 1-2
shows the TRINITY site with its major installations.

* Throughout this report, surface distances are given in metric units.
The metric conversion factors include: 1 meter = 3.28 feet; 1 meter =
1.09 yards; and 1 kilometer = 0.62 miles. Vertical distances are
given in feet; altitudes are measured from mean sea level, while
heights are measured from surface level, unless otherwise noted.

Ground zero for the TRINITY detonation was at UTM coordinates
630266.** Three shelters, located approximately 9,150 meters (10,000
yards) north, west, and south of ground zero, were built for the
protection of test personnel and instruments. The shelters had walls
of reinforced concrete and were buried under a few feet of earth. The
south shelter was the Control Point for the test (12). The Base Camp,
which was the headquarters for Project TRINITY, was located
approximately 16 kilometers southwest of ground zero. The principal
buildings of the abandoned McDonald Ranch, where the active parts of
the TRINITY device were assembled, stood 3,660 meters southeast of