In August 1914 most Militia units were mobilized for local protective duties. They then contributed volunteers to the early contingents proceeding overseas.  Later most would raise complete units for the Canadian Expeditionary Force; these either served in France and Flanders or were broken up to provide reinforcements for the Canadian Corps.  Militia home service continued throughout the war, with some expansion of existing units.

The 30th Regiment, British Columbia Horse served from 1914 to 1918 without change to its organization.

In 1915, the 31st Regiment, British Columbia Horse moved its headquarters from Merritt to Kamloops and transferred "C" Squadron from Wallachin to Langley Prairie.³⁸  In 1916, "B" Squadron was re-located to Vancouver from Salmon Arm.³⁹

After the creation of "H" Company in Penticton in late 1914, the 102nd Regiment, Rocky Mountain Rangers retained its eight-company organization until 1919.  

The relatively new 107th East Kootenay Regiment went through a number of organization changes as it shook itself out.  The following localization of battalion and company headquarters was authorized in January 1915: ⁴⁰

In 1915 and 1916, there would be changes to the organization of the 107th East Kootenay Regiment that would see its footprint reduced.  In 1915, "E" Company transferred from Elko to Fernie, "G" Company from Athalmer to Nelson, and "H" Company from Golden to Nelson.⁴¹  In 1916, "C" Company would be relocated from Cranbrook to Michel.⁴²

In 1918, at the close of the First World War, the Militia in the British Columbia interior had the following structure:⁴³

30th Regiment, British Columbia Horse

31st Regiment, British Columbia Horse

102nd Regiment, Rocky Mountain Rangers

107th East Kootenay Regiment

Independent Company of Rifles	Grand Forks
	MAP BC Units circa 1918

Places mentioned in this section -  Click for Maps