You have a couple of options of airports to fly into.

Seattle Tacoma International Airport (SEA)

Most common airport, located approximately 50 minutes from Snohomish, WA.

Everett Paine-Field (PAE)

This one's a lot closer to us, but likely more expensive. Approximately 23 minutes from Snohomish, WA.

We highly recommend renting a car from the airport you arrive in to utilize during your trip.