During the Boer War in South Africa, Canadian mounted troops gathered information of intelligence value with Strathcona's Horse and British scout units. Canadian intelligence efforts in South Africa led to the appointment on 6 February 1901 of Lieutenant-Colonel Victor Brereton Rivers, RCA, as the first intelligence staff officer of the Canadian Militia. Shortly after, on 1 April 1903, the Corps of Guides was created in the Canadian Militia. Under the new structure, a district intelligence officer responsible to director general of military intelligence (DGMI) was appointed to oversee Corps of Guides units established in each of Canada's 12 military districts. The first DGMI, Lieutenant-Colonel W.A.C. Denny, had a very small staff overseeing information collection and mapping, and approximately 185 militia officers serving the Canadian Corps of Guides.