All United States citizens, including foreign nationals, traveling by air, land, or sea to Canada must present a passport book, passport card, or other Western
Western Hemisphere Travel Initiative

The Western Hemisphere Travel Initiative (WHTI) is a U.S. law when entering the United States from into Canada and the United States by
Crossing the US Canadian Border

Canada identification requirements when crossing border from US. What Victoria Clipper passengers need to know when traveling
For US Residents Entering Canada

United States Residents Entering Canada. Passports. Passports to enter Canada or return to the United States are not required for native-born citizens of either country.