Do I need a passport to travel to Canada?
When planning a trip to Canada, it's important to see what the latest entry requirements are for foreigners. US citizens traveling to Canada must carry a valid passport, passport card, or NEXUS card. Though children under 16 need only present proof of U.S. citizenship. Additionally, travel visas may be required prior to arriving in Canada.
Globerouter recommends checking the lastest entry requirements on the Government of Canada's website: https://travel.gc.ca/returning/travelling-to-canada.