Was there a US Army Camp at Mon Repos?

In March 2009 Michael Latter told me that a Mon Repos turtle rookery ranger had told him that there was a US Army training base (most probably US although it could have been Australian) at Mon Repos near Bundaberg during WWII. She told Michael that at the southern end of the beach there was a large concrete slab there for bringing up amphibious vehicles from the beach. Mon Repos Beach is just north of Bargara.

Michael was not able to locate any slabs but he did find what looked like two possible makeshift machine gun posts made of rocks with an entrance on one side. These where located at the semi top of a hill looking down upon a large open area. A fair percentage of the area also seemed unnatural.