I'm on a New Zealand passport.
From most US Embassy webpages:
The Visa Waiver Program (VWP) enables nationals of certain countries, including Australia, New Zealand, and the U.K., to travel to the United States for tourism or business for stays of 90 days or less without obtaining a visa, if certain requirements are met. Under the VWP, time spent in Canada, Mexico, and adjacent islands counts towards the maximum of 90 days stay allowed under the program.
I'll be there on a 1-year working holiday visa starting when I arrive in Vancouver. I'm spending 3 days in Hawaii en route to Vancouver. This seems to imply that 90 days after landing in Hawaii, my time will be up and I won't be able to get back into the US, as my living in Canada will not reset the clock. What if after this time I want to say, pop across the border to Seattle? How can I restart the 90 days, without having to resort to say, flying to Japan and back just to reset it?