This just in from our colleagues at NOTO ( the Northern Ontario Tourist Outfitters Association, of which we are a long-standing member):
We are hearing from many operators reports of stepped-up screening of guest entering Canada from the US. Although the requirements have not changed, border officials are becoming much more careful about checking for valid entry documents.
Despite the recent rumblings about passport requirements for US guests to re-enter their country, this provision is not scheduled to come into effect for a while yet. What is in effect, and has always been a requirement, is the need to show proof of citizenship.
Despite what may have been accepted in the past, a driver's license is not proof of citizenship! Because it has a photo, it is useful to provide positive identification, along with a proof of citizenship document, such as a birth certificate. A passport provides both identification and proof of citizenship, so it is the best document for frequent travelers.
The requirements for entry into Canada are exactly the same as the requirements guests have to meet to re-enter the US when they go home. Although driver's licenses may have been accepted at some border crossings in the past, they have never been an acceptable proof of citizenship.
By far the best advice for anyone who travels between the US and Canada is to obtain a passport. It is considered the most secure form of identification, and will definitively help minimize problems at the border. Until the new requirements come into effect, photo ID plus proof of citizenship is still acceptable.
Heightened border security is a fact of life we all have to live with. However, if you have the required documents ready when you arrive at the border, most border crossings are as simple and routine as they ever were.