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Historic Sites of Manitoba: Fallout Reporting Post JG3 (Northern Manitoba)

Link to:
Photos & Coordinates | Sources

In the spring of 1962, at the height of the Cold War, the Canadian government began building a nation-wide Nuclear Detonation and Fallout Reporting System (NDFRS) to measure the pattern and intensity of radioactive fallout in the event of a nuclear explosion. A network of 2,000 small Fallout Reporting Posts, 200 of them distributed throughout Manitoba, would be constructed to take local fallout measurements. In Manitoba, results from each Fallout Reporting Post would be transmitted to Filter Centres located at the Pine Falls Armoury and Brandon Armoury where teams of women in the Canadian Women’s Army Corps would summarize and pass on the data to one of three Nuclear Detonation Reporting Posts (NUDET), located at RCAF Portage la Prairie and RCAF Gimli, and in the Great Falls Generating System. NUDETs would use the data to determine the location of the explosion and its fallout yield, and transmit this information to the Regional Emergency Government Headquarters (REGHQ) at Camp Shilo.

At least 100 of the 200 Fallout Reporting Posts in the Manitoba complement were constructed by mid-1962. Some were situated in railway stations, buildings belonging to federal and provincial agencies, and RCMP detachment offices. Others in more remote locations were built underground to protect the operators from radiation. This post, designated as JG3, consisted of a vertical access tunnel made of corrugated metal that led down to a second, larger corrugated metal cylinder that housed the radiation monitoring equipment, storage shelves for food, water, and other supplies, and beds for two people. The post, located near Beaver Creek Provincial Park on the west side of Lake Winnipeg north of Grindstone Point, remained in relatively good condition at the time of a mid-2019 site visit.

Photos & Coordinates

Entrance to Fallout Reporting Post JG3

Entrance to Fallout Reporting Post JG3 (September 2019)
Source: Christine Loff

Entrance to Fallout Reporting Post JG3

Entrance to Fallout Reporting Post JG3 (September 2019)
Source: Christine Loff

Interior of Fallout Reporting Post JG3

Interior of Fallout Reporting Post JG3 (August 2019)
Source: Elise Watchorn

Site Coordinates (lat/long): N51.39922, W96.90781
denoted by symbol on the map above

See also:

Historic Sites of Manitoba: Fallout Reporting Post GH3 (Northern Manitoba)

Historic Sites of Manitoba: Fallout Reporting Post KE4 (Northwest Angle Provincial Forest)


“Exercise planned to confirm fallout patterns,” Brandon Sun, 11 April 1962, page 3.

“100 fallout stations set in province,” Winnipeg Tribune, 23 July 1962, page 25.

“Fallout post still ‘voiceless’,” Winnipeg Free Press, 28 August 1962, page 3.

Simple shelters? Monitoring radioactive fallout across Canada, 1959-63” by Andrew Burtch, Canadian Military History, Volume 20, Number 4, Autumn 2011, pages 49-62.

This page was prepared by Elise Watchorn, Gordon Goldsborough, and Christine Loff.

Page revised: 18 December 2020

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