Contained within the 3rd Edition (1957) of the Atlas of Canada is a map that shows the portions of land in four condensed maps which illustrate the kind of forest maps that were being prepared from air photographs with a minimum of groundwork by the Forestry Branch of the Department of Northern Affairs and National Resources in the 1950s. Such maps not only show more detail than can be shown on a general forest regions map but also enable sample areas to be located which, when investigated on the ground, provide estimates of timber volumes. These maps are also of value to those responsible for forest protection and the suppression of forest fires. The first of the maps reproduced here illustrates an area of almost continuous forest in the rough terrain of the Alberta foothills (from sheet 82 0/14 - Marble Mountain). The second shows forested areas broken only by a few scattered farms (from sheet 31 0/10 - Mitchinamecus River, Quebec). The third shows an area almost equally divided between farm and f