The above link may not work. But here is the answer.
6. Do I need a multiple entry Temporary Resident Visa if I intend to travel to the United States during my visit to Canada?
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 another 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 duration of your stay in Canada.
The above link may not work. But here is the answer.
6. Do I need a multiple entry Temporary Resident Visa if I intend to travel to the United States during my visit to Canada?
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 another 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 duration of your stay in Canada.