As part of its contribution to the building of irrigation canals in southern Alberta, the federal government produced this map of the foothills. It provided engineers with a basis from which to calculate steam flows and plan the construction of ponds for containing water used in the irrigation canals further east. When compiling this map, Wheeler used the relatively new photo-topographic process that Canadian surveyors developed for mountainous regions. It involved special cameras and the exposure of overlapping panoramic photographs from mountain tops.