I'm a British citizen flying from London to Seattle in late May. My plan is to stay in Seattle for a few days, then travel south to Portland before flying up to Vancouver, Canada. From there I plan to spend a little over a week travelling east from Vancouver to Calgary, from where I will fly back to England. The whole trip will last less than 3 weeks.
I've searched at great length to find information on the rules regarding how this would work with Visa Waiver Program eligibility, as travelling into a bordering country doesn't count as leaving the US for the purpose of the 90 day stay limit. There's so much conflicting information though that it's stressing me out a bit!
Does anybody have any advice as to what might be my best course of action? Will I have problems entering the US because of this and what might I need to prove my exiting the US if I'm allowed in?
I've got my flights booked already, so I intend to evidence my full itinerary when arriving in the US (printouts of flight/bus bookings, hotels etc.), and I have my ESTA application complete. Is this enough?