Abbotsford Airport, Abbotsford, BC (CYXX)
Correctly identified first by Elliott Drucker

Just a stone's throw across the border and an easy flight from anywhere in western Washington, Abbotsford is a big old ex-military base but is a friendly and low-key entry point for visiting US pilots. It's an ideal place to clear Canadian customs, and also home to Canada's largest airshow held every August.