Border Crossing Information:
www.travel.state.gov/travel
www.dhs.gov/xtrvlsec/crossingborders/index.shtm
http://cbsa-asfc.gc.ca
www.gonorthwest.com

As of June 1, 2009, US citizents require a passport to re-enter the US.

You can bring additional alcoholic beverages and cigarettes, but make sure to claim the actual amount. You will be charged duty and taxes, but it will still remain less expensive than if you purchased them in Canada. Whatever you do, don't try to smuggle the additional amount across the border. It is not worth it. If traveling with children other than immediate family, have a signed letter of permission from the children's parents. When clearing customs for entry into Canada, remember to answer the questions politely and precisely. Don't try to be funny, cute or clever. They don't appreciate improper attitudes that often lead to delays, when they decide to check you out in response to the answer to their questions. Always be honest to their questions.