CSIA (Canadian Ski Instructors Alliance) is the governing body for ski instructors in Canada. If you want to become a ski instructor in Canada you will need to apply for a working visa, and to qualify for a visa you will need to hold a minimum of a BASI Level 2 qualification (or equivalent). Once you have your BASI Level 2 qualification, you will then be able to start applying for positions with Canadian Ski Schools. If you are successful, the ski school will give you a job offer followed by a contract, they will then normally help you to obtain your visa to work for them.
Obtaining the visa is not completely straight forward. Firstly, the ski school will need to apply for approval to be able to employ a foreign worker. If they are given approval, they will be sent an approval code which the instructor can take to the Embassy to apply for the visa. With this visa, instructors are given permission to work in a particular resort until the end of the winter season.
Alternatively, without a job offer, you can apply for a working holiday visa before heading to Canada. Like Australia, resorts in Canada hold hiring clinics, usually in October, if they are still looking for instructors for the winter.