Thank you for taking the time to get information about a found cat. It is much better for the cat if you attempt to find the owner. If you take the cat to an SPCA shelter, it might be euthanized.
First, provide the cat with food, water, and indoor shelter, particularly at night as there is always the danger of local wildlife such as coyotes. Also, provide veterinary care if needed. Be sure to place a free found ad in all the local papers and in the Sun and Province. Remember, these are free ads, so take advantage of that. The ad should run repeatedly for as long as possible. Watch the lost ads in case the stray shows up there. Notify local vets as the owner may have contacted them. Put posters around the area large enough to read from a car. Keep posters simple: just write FOUND, a short description, and your phone number. Notify local paper carriers and postal workers. Take a poster to your local SPCA shelter, and be certain that it is put up. If you do not find the owner after a few weeks, try to place the cat in an adoption home yourself.