I know of two growers in the Skagit Valley that have display gardens. One is Tulip Town and the other RoozenGaarde (Washington Bulb Company). I visited both this year and found the display gardens and adjacent fields quite colorful. The Tulip Festival goes on for the month of April. I read that the peak blooming would be about mid-month so, that's when I went.
Skagit Valley Tulips
Mount Vernon, WA, USA