What do you need to enter canada?

From CBSA " If you are a citizen of the United States, you do not need a passport to enter Canada. However, you should carry proof of your citizenship, such as a birth certificate, certificate of citizenship or naturalization, as well as photo identification. read more

Canadian law requires all persons entering Canada from the U.S. by car present proof of citizenship and identity. A passport fulfills both of these requirements for U.S. citizens. A U.S. citizen can also use his Nexus card to fulfill both of these requirements. read more