Camp X closed in April 1944. It had served its purpose, and the personnel were needed elsewhere. The instructors returned to Britain or the U.S., and the Canadian staff moved on to other jobs in Canada. It's impossible to know how many men were trained there — records were kept secret, destroyed or scattered across three different nations' bureaucracies — but estimates range from a few hundred to 2,000 or 3,000 [source: Montgomery]. The camp's training regimen became so infamous and prestigious that far more men claimed to have trained there than actually did.
However, the buildings still existed after the camp closed, and they found some use during the Cold War. Immediately after the end of the World War II, a cipher clerk named Igor Gouzenko defected from the Soviet Union to Canada, bringing with him information on Soviet secret agents. British and American intelligence officials interviewed him at Camp X, where he was safe from potential interference from Soviet agents.
Control of the Hydra station was transferred to the Canadian military. Hydra functioned as a signal intercepting station as the final months of World War II played out against Japan, and it was used to intercept Soviet radio transmissions during the early years of the Cold War. By 1969, the station's equipment was no longer sophisticated, and the site was officially decommissioned and sold to local municipal governments.
Amid concerns that the camp might contain unexploded ordnance (weapons that did not explode but still pose a risk of doing so) from all the explosive training, the Canadian army bulldozed almost all the buildings directly into Lake Ontario in the late 1970s. Only one building survived: part of one of the barracks, which was moved and used as a storage building by an animal shelter before a nearby college began restoring it [source: Calzavara].
Today, Intrepid Park (named after William Stephenson's wartime moniker) marks the location of Camp X. The park is only a sliver of the original 260-acre (105-hectare) site, which is covered by warehouses. A plaque commemorates the men who trained there and what they accomplished in the war, and every November a Canadian veterans' group holds a memorial on the site.