A single entry visa allows you to enter Canada only once. However, this visa may also be used for repeated entries into Canada from the USA or St. Pierre and Miquelon provided you do not enter any other country. Such entries must occur within the time that was granted for your stay in Canada.
If you intend to travel to the United States during your visit to Canada, you do not need a multiple-entry visa in order to re-enter Canada directly from the United States during the authorized duration of your stay in Canada.
If you intend to travel to the United States during your visit to Canada, you do not need a multiple-entry visa in order to re-enter Canada directly from the United States during the authorized duration of your stay in Canada.