From time to time, you may find that you are not getting an exact city for the numbers you are searching for in Canada. In some parts of Canada, the geo-data we receive back from the carriers does not provide city level detail. We are working on getting better information for you on these numbers.
In the meantime, we recommend this very helpful website AllAreaCodes.com you can see a map of Canada and the area codes that belong to certain areas. Also you can type in the City you are looking for and be provided with the area code. Also listed below are Wiki articles that may help as well.
Wikipedia Articles Detailing Exchanges for each City by Area Code:
Area Code 587 in Alberta: http://en.wikipedia.org/wiki/Area_code_587
Area Code 403 in Alberta: http://en.wikipedia.org/wiki/Area_code_403
Area Codes 778 and 236 in British Columbia: http://en.wikipedia.org/wiki/Area_codes_778_and_236