world into the atomic age. All life on Earth has been touched by the
event which took place here.

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 McDonald ranch house, where the plutonium core to
the bomb was assembled. On your visit to Trinity Site you will be
able to see ground zero and the McDonald ranch house. In addition, on
your drive into the Trinity Site area you will pass one of the old
instrumentation bunkers which is beside the road just west of ground
zero.



The Manhattan Project


The story of Trinity Site begins with the formation of the Manhattan
Project in June 1942. The project was given overall responsibility of
designing and building an atomic bomb. At the time it was a race to
beat the Germans who, according to intelligence reports, were building
their own atomic bomb.

Under the Manhattan Project three large facilities were constructed.
At Oak Ridge, Tenn., huge gas diffusion and electromagnetic process
plants were built to separate uranium 235 from its more common form,
uranium 238. Hanford, Wash. became the home for nuclear reactors
which produced a new element called plutonium. Both uranium 235 and
plutonium are fissionable and can be used to produce an atomic