My wife is visiting me in US with a visitor visa, and she is going to Vancouver to visit her cousin next month. I have couple of questions for people who have traveled to YVR from US with a Visitor Visa.
1) Where do you hand in the I-94? Before you boarding the plane in US or after you landed in YVR.
2) When coming back, you have to go through the U.S Custom and Immigration at YVR, does this mean you don't have to go through the Custom again after you landed in US?

Thank you ver much.