Cap Badge - 141st (Fort Frances, Ontario), Battalion, CEF also known as the 141st (Rainy River District) Battalion (Border Bull Moose), CEF The 141st Battalion, CEF was a unit in the Canadian Expeditionary Force during the First World War. Based in Fort Frances, Ontario, the unit began recruiting in late 1915 in Rainy River district of northern Ontario. After sailing to England in April 1917, the battalion was absorbed into the 18th Reserve Battalion on May 7, 1917.