Traveling into Canada from the U.S. just for a few hours?

My mom and I want to drive into Canada, from Washington, just to visit for a few hours. I was wondering what documentation do we all need to have with us. I looked at the questions on here but they're all over a couple months old and I want updated information. Thanks for your help.

Passports.

I just came back from Canada on Tuesday!
My whole family drove there from Seattle after I flew there from Los Angeles.
Really, all you need is your passport.
Nothing else, but they will ask you some questions such as why you're going over, did you brink any alcohol or cigarettes etc with you, how long will you be there, where are you going inside Canada, just stuff like that.

You don't even need a passport if you're driving.

All you need is photo ID and proof of citizenship (i.e. birth certificate). However, if you do have passports, they satisfy both the requirements.