The distribution of H. capsulatum in Canada is not as well documented as in the US. The St. Lawrence Valley is probably the best known endemic region based both on case reports and on a number of skin test reaction studies that were done between 1945 and 1970. The Montreal area is a particularly well documented endemic focus, not just in the agricultural regions surrounding the city but also within the city itself. The Mount Royal area in central Montreal, especially the north and east sides of Mt. Royal Park, showed exposure rates between 20 and 50% in schoolchildren and locally lifetime-resident university students. A particularly high rate of 79.3% exposure was shown in St. Thomas, Ontario, south of London, Ontario, after 7 local residents had died of histoplasmosis in 1957. Based on numerous small regional studies, histoplasmin skin test reactors form ca. 10-50 % of the population in much of southern Ontario and in Quebec's St. Lawrence Valley, ca. 5% in southern Manitoba and some northerly parts of Quebec (e.g., Abitibi-Témiscamingue), and ca. 1% in Nova Scotia. Exposure of aboriginal Canadians occurs remarkably far north in Quebec, but has not been reported in similar boreal biogeoclimatic zones in many other parts of Canada. Recently and remarkably, a cluster of four indigenously acquired cases of histoplasmosis was shown to be associated with a golf course in suburban Edmonton, Alberta. Examination suggested that local soil was the source.