While the American Forces were based at Archerfield, the area to the west of the intersection of Mortimer Road and Beatty Road was occupied by Camp Buckley, and large igloo hangars were built to the north of the quarry. A taxiway linking the igloos to the main aerodrome to the west passed close by the northern side of the quarry, and the air raid shelter was constructed to provide protection for military personnel stationed nearby. World War II aerial photographs show that the water level in the quarry used to be below the rock shelf on which the shelter was built. They also indicate that the building was freestanding at that time, in the middle of a cleared platform. Earth has since collapsed or been moved onto the shelf around the bunker, giving it the appearance of having been built into the quarry wall. The quarry side of the bunker was protected by an outer curtain wall, which contained entrances to two tunnels leading into the main bunker. There was about a metre between the curtain wall and the edge of the rock shelf. The Allied Works Council Minutes of 8 January 1943 record that a bomb proof building for United States Air Corps Operations had been built near the American camp, and this may refer to the shelter in the quarry.
