The area was first used as a mobilisation and training area during World War I. During the early 1920s, an ordnance store and rifle range were built on the site. In 1939, the area was formally established as Puckapunyal Camp: the name was taken from the Aboriginal name for a large hill within the training area, which has been variously translated as "death to the eagle", "the outer barbarians", "the middle hill", "place of exile", and "valley of the winds". The base was used to train the Second Australian Imperial Force, as other Army establishments were at capacity training Militia units. The original site was too small for wartime training, and an additional were acquired. As well as Australian units, the United States Army's 41st Infantry Division trained at Puckapunyal.