My wife and I are from New Zealand. In mid March we will be in Kamloops after 2 weeks skiing and will hire a rental for around 2 to 3 weeks to explore the North West USA. We have previously travelled extensively in British Columbia and Alberta so this trip is aimed more at the USA than Canada. We would like to get as far as Yellowstone and take in Portland and Seattle on the way back to Vancouver. What would be a suitable route at that time of year and what should we see along the way.